How should I assess a woman who is considering starting a combined oral contraceptive (COC)?

• For information on assessing a woman who is considering starting a combined oral contraceptive (COC), see the section on combined hormonal contraception in the CKS topic on Contraception - assessment.

Amenorrhoea, postpartum, termination of pregnancy, or miscarriage

• If the woman is amenorrhoeic:
  • Start the combined oral contraceptive (COC) at any time, if it is reasonably certain that the woman is not pregnant.
    • Additional contraception is required for 7 days (9 days for Qlaira^®).
• If the woman is postpartum and not breastfeeding:
  • Start the COC on day 21 postpartum if there are no additional risk factors for venous thromboembolism.
    • Additional contraception is required for 7 days.
  • If it has been more than 21 days postpartum and menstrual cycles have returned, start the COC as for other women having menstrual cycles.
  • If it has been more than 21 days postpartum and menstrual cycles have not returned, start the COC as for a woman who is amenorrhoeic.
• If the woman is postpartum and breastfeeding: 
  • Do not start a COC if the woman is less than 6 weeks postpartum.
  • After 6 weeks and before 6 months postpartum, start the COC as for postpartum women who are not breastfeeding.
• If the woman has had a miscarriage or termination of pregnancy:
  • Start the COC within 5 days of surgical or the first stage of medical termination (except Qlaira^® and Zoely^®). No additional contraception is required.
    • Start Qlaira^® or Zoely^® on day 1 post-termination. No additional contraception is required.
    • If the COC is started at any other time, provided it is reasonably certain that the woman is not pregnant, advise the woman to use a barrier method of contraception (such as condoms) for 7 days (9 days for Qlaira^®).
    • Note: If gestation is 24 weeks or more, start the COC as for a woman who is postpartum.

Which combined oral contraceptive (COC) should I offer first-line?

• First-line options are monophasic preparations containing 30 micrograms of oestrogen, plus either norethisterone or levonorgestrel.
• However, consider the woman's preference, as any combined oral contraceptive (COC) can be offered first-line.
• Prescribe up to 12 months supply for women who are initiating or continuing CHC.

When can a woman start using a combined oral contraceptive?

Specific advice for women who are amenorrhoeic, postpartum, post-termination, or post-miscarriage is summarized in the section Amenorrhoea, postpartum, termination of pregnancy, or miscarriage.

If the woman is not currently using a regular method of contraception or using a barrier method (such as condoms):

• Start the combined oral contraceptive (COC) on day 1 of the menstrual cycle. 
  • No additional contraception is required.
• If the COC is started on days 2–5 of the menstrual cycle: 
  • No additional contraception is required unless the woman is starting Qlaira^® or Zoely^®.
    • If the woman is starting Qlaira^®, advise her to use a barrier method of contraception (such as condoms) for the first 9 days.
    • If the woman is starting Zoely^®, advise her to use a barrier method of contraception (such as condoms) for the first 7 days.
• If the COC is started at any other time in the menstrual cycle, provided a barrier method has been used consistently and correctly and/or it is reasonably certain that the woman is not pregnant:
  • Advise the woman to use a barrier method of contraception (such as condoms) for the first 7 days (9 days for Qlaira^®).
  • Inform the woman that medical advice may differ from that included in the packet of pills, but it is based on good medical practice.
• If pregnancy cannot be excluded and the woman wishes to start hormonal contraception without delay:
  • Prescribe the COC and advise the woman to take a pregnancy test no sooner than 3 weeks after the last episode of unprotected sexual intercourse (UPSI).

If the woman is starting a COC after oral emergency contraception:

• For levonorgestrel, advise the woman to start the COC immediately and use a barrier method of contraception (such as condoms) for the first 7 days (9 days if taking Qlaira^®).
• For ulipristal acetate, advise the woman to start the COC 5 days after taking ulipristal acetate, and to use a barrier method of contraception (such as condoms) for this time and the next 7 days (9 days if taking Qlaira^®).

If the woman is switching from another COC, the combined contraceptive patch, or the combined vaginal ring:

• Start the COC on the day after the last active pill, patch, or vaginal ring. There is no need to wait for the next menstrual period. 
  • No additional contraception is required.
• If the woman decides to take a 7-day hormone-free interval (or a 4-day hormone-free interval for Zoely^®) before starting the new COC, assess the need for additional contraception and emergency contraception. See the CKS topic on Contraception - emergency for more information.

If the woman is switching from a progestogen-only pill (except desogestrel) or levonorgestrel intrauterine system (LNG-IUS):

• Start the COC at any time in the menstrual cycle provided it is reasonably certain that the woman is not pregnant. 
  • There is no need to wait for the next menstrual period.
• Advise the woman to use a barrier method of contraception (such as condoms) for the first 7 days (9 days for Qlaira®).

If the woman is switching from the progestogen-only injectable, or a desogestrel-only pill:

• Start the COC at any time up to when the repeat of injectable is due, or the next day after the progestogen-only pill.  
  • No additional contraception is required.

If the woman is switching from the drospirenone progestogen-only pill:

• Days 8-24 (active pills) — start immediately. No additional precautions required. 
• During HFI (placebo pills, days 25–28) or days 1–7 (active pills) after HFI and no UPSI since start of HFI — start immediately and advise the woman to use a barrier method of contraception (such as condoms) for 7 days.
• During HFI (placebo pills, days 25–28) or days 1–7 (active pills) after HFI and UPSI since start of HFI — restart/continue drospirenone until 7 consecutive pills taken then switch as for days 8–24.

If the woman is switching from a progestogen-only implant that has been in situ:

• For 3 years or less — advise the woman to start the COC immediately and that no additional contraception is required.
• For 3 to 4 years  — rule out pregnancy and advise the woman to start the COC immediately and use a barrier method of contraception (such as condoms) for the first 7 days. Advise the woman to take a pregnancy test 21 days following last UPSI (if applicable).
• For more than 4 years and has not had unprotected sexual intercourse (UPSI) within the last 3 weeks  — rule out pregnancy and advise the woman to start the COC immediately and use a barrier method of contraception (such as condoms) for the first 7 days.
• For more than 4 years and has had UPSI within the last 3 weeks — consider the need for emergency contraception [See the CKS topic on Contraception - emergency for more information]. Otherwise, rule out pregnancy and advise the woman to start the COC immediately and use a barrier method of contraception (such as condoms) for the first 7 days, and take a pregnancy test at 21 days following UPSI. 

If the woman is switching from a copper intrauterine device (Cu-IUD):

• Remove the IUD on day 1–5 of the menstrual cycle and start the COC on the same day (except if starting Qlaira^®). 
  • No additional contraception is required.
• If starting Qlaira^®, remove the IUD on day 1 of the menstrual cycle and start the COC on the same day.
  •  No additional contraception is required.
• If the IUD is removed at any other time in the menstrual cycle: 
  • Advise the woman to use a barrier method of contraception (such as condoms) for the first 7 days of pill taking (9 days for Qlaira^®).
• If the COC is started 7 days before removal of the IUD (9 days for Qlaira^®):
  • No additional contraception is required. 

Excluding pregnancy

• Health professionals can be ‘reasonably certain’ that a woman is not currently pregnant if any one or more of the following criteria are met and there are no symptoms or signs of pregnancy:
  • She has not had intercourse since the start of her last normal (natural) menstrual period, since childbirth, abortion, miscarriage, ectopic pregnancy, or uterine evacuation for gestational trophoblastic disease.
  • She has been correctly and consistently using a reliable method of contraception.
    • For the purposes of being reasonably certain that a woman is not currently pregnant, barrier methods of contraception can be considered reliable provided they have been used consistently and correctly for every episode of intercourse.
  • She is within the first 5 days of the onset of a normal (natural) menstrual period.
  • She is less than 21 days postpartum (non-breastfeeding women).
  • She is fully breastfeeding, amenorrhoeic, and less than 6 months postpartum.
  • She is within the first 5 days after abortion, miscarriage, ectopic pregnancy, or uterine evacuation for gestational trophoblastic disease.
  • She has not had intercourse for more than 21 days and has a negative high-sensitivity urine pregnancy test (able to detect human chorionic gonadotrophin [hCG] levels around 20 mIU/ml).

What types of combined oral contraceptive (COC) are available?

• Combined oral contraceptives (COCs) contain both an oestrogen (usually ethinylestradiol) and a progestogen (such as levonorgestrel, norethisterone, desogestrel, gestodene, or drospirenone) component. Qlaira^® and Zoely^® contain estradiol valerate which is metabolized to estradiol, an oestrogen hormone that is found naturally in the human body.
• COC preparations differ according to:
  • How the doses vary over the menstrual cycle.
    • In monophasic COCs, the amount of oestrogen and progestogen in each active tablet is constant throughout the cycle.
    • In phasic COCs, the amounts of oestrogen and progestogen vary over the cycle.
  • The dose/strength of oestrogen.
    • Low-strength COCs contain 20 micrograms of ethinylestradiol.
    • Standard-strength preparations contain 30–35 micrograms of ethinylestradiol in monophasic COCs and 30–40 micrograms of ethinylestradiol in phased preparations.
  • The type of progestogen they contain.
  • The presence or absence of a pill-free interval.
    • Most COCs are packaged as calendar strips of 21 active tablets. One tablet is taken daily for 3 weeks; no tablet is taken during the following 7 days (pill-free interval). However, to aid compliance, some products are packed with 21 active tablets and 7 inert or placebo tablets; a tablet is taken every day of the 28-day cycle (no pill-free interval).

Table 1. Combined oral contraceptives (COCs) currently marketed in the UK include:

Basis for recommendation

This information is based on the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guidelines Combined hormonal contraception [CoSRH, 2023a], Contraception after pregnancy [CoSRH, 2020], Quick starting contraception [CoSRH, 2017], and Switching or starting methods of contraception [CoSRH, 2023b], thr Royal College of Obstetricians and Gynaecologists (RCOG) guideline Best practice in post-abortion contraception [RCOG, 2022], the UK Medical Eligibility Criteria for contraceptive use [CoSRH, 2016], and the British National Formulary (BNF) [BNF, 2024].

How should vomiting or diarrhoea be managed in women taking a combined oral contraceptive (COC)?

• For all combined oral contraceptives (COCs) except Qlaira^® and Zoely^®:
  • If a woman vomits (for any reason) within 3 hours of taking a combined oral contraceptive (COC), advise her to take another pill as soon as possible.
  • If vomiting or diarrhoea persists for more than 24 hours, advise her:
    • To follow the instructions for missed pills, counting each day of vomiting and/or diarrhoea as a missed pill.
    • To avoid sexual intercourse or use a barrier method of contraception (such as condoms) during the illness interval and for 7 days afterwards.
    • That if the illness occurs while taking the last 7 pills, she should omit any pill-free interval (or inactive tablets) and start the next cycle immediately.
• For Qlaira^® and Zoely^®:
  • If a woman vomits within 3–4 hours of taking an active pill, advise her to take the next tablet as soon as possible, ideally within 12 hours of the usual time of pill taking for Qlaira^® or 24 hours for Zoely^®.
  • If more than 12 hours elapse for Qlaira^® or 24 hours for Zoely^®, advise the woman to follow the missed pills advice for Qlaira^® or missed pills advice for Zoely^®.
  • If the woman does not want to change her normal pill-taking schedule, advise her to take the corresponding pill(s) needed from another pack.

How should I manage a woman who becomes pregnant whilst taking a combined oral contraceptive (COC)?

• If a woman becomes pregnant while taking the combined oral contraceptive (COC) pill and she wishes to continue with the pregnancy:
  • Advise her to stop taking the pill.
  • Inform her that there is no evidence of harm to the baby or the mother if pregnancy occurs whilst using the COC.

Basis for recommendation

These recommendations are based on the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guidelines Combined hormonal contraception [CoSRH, 2023a], UK Medical Eligibility Criteria for contraceptive use [CoSRH, 2016], Drug interactions with hormonal contraception [CoSRH, 2022], and the manufacturer's Summaries of Product Characteristics [EMC, 2022a; EMC, 2023a].

Advice about tailored CHC regimens

• The traditional 21/7 CHC regimen with a monthly withdrawal bleed confers no health benefit over other patterns of CHC use. Symptoms associated with the hormone-free interval (HFI) can be problematic and ovarian activity during a 7-day HFI could risk escape ovulation (particularly with lower doses of EE and if use is not perfect). Tailored CHC regimens can be safely used to avoid withdrawal bleeds and associated symptoms and theoretically reduce the risk of contraceptive failure [CoSRH, 2023a]. 

Safety of tailored regimens [CoSRH, 2023a]

• Direct data comparing risk of cardiovascular events and cancer between extended and standard CHC regimens are lacking, however, the FSRH states that indirect evidence regarding cardiovascular risk is reassuring.
  • In a Phase 3 trial of 20 micrograms ethinylestradiol/drospirenone (EE/DRSP) combined oral contraceptive (COC), 1067 women were randomised to standard cyclical, flexible extended or fixed extended pill-taking regimens for 1 year. A total of 755 women then entered an extension phase, taking the flexible extended regimen. Metabolic and haemostatic parameters, serum hormone levels and blood pressure were similar in all groups. The number of serious adverse events was very low in all groups.
  • A smaller trial which randomised 78 women to use extended or standard cyclical regimens of 30 micrograms EE/DRSP COC found no statistically significant differences in carbohydrate or lipid profiles between the two groups over 6 months of use.
  • In a third trial, 174 women were randomised to cyclical or continuous use of 20 micrograms EE/levonorgestrel (LNG) COC (the dose of LNG was different in the two groups). The authors concluded that after 13 months of use, carbohydrate metabolism, lipid profile and haemostatic variables were broadly similar between the groups, but that further studies would be required to assess long-term continuous CHC. 
  • Haemostatic parameters were also reported to be similar among 187 women randomised to extended or cyclical use of 30 micrograms EE/LNG COC for 6 months.

Bleeding patterns with extended CHC regimens [CoSRH, 2023a]

• A Cochrane Review of randomized controlled trials (RCTs) reported that in most studies bleeding patterns with extended CHC regimens were equivalent or improved compared to standard regimens.
• A systematic review that included both RCTs and observational studies concluded that overall, the total number of days of bleeding was lower with continuous or extended regimens than with cyclical use of CHC. However, there was an increase in breakthrough bleeding during the first months of use of continuous or extended regimens, its frequency and intensity subsequently decreased over time.
• Limited evidence suggests that bleeding patterns with continuous or extended use of the combined transdermal patch (CTP) and combined vaginal ring (CVR) show a similar reduction in bleeding/spotting days over time to that seen with extended use of COC.
• One study compared bleeding patterns in 139 existing cyclic COC users who were randomised to continuous use for 180 days of COC containing 30 micrograms EE/100 micrograms LNG, 20 micrograms EE/100 micrograms LNG, 30 micrograms EE/1000 micrograms norethisterone (NET) or 20 micrograms EE/1000 micrograms NET (only the first of these is available in the UK). The study suggested more favourable bleeding patterns (more amenorrhoea and fewer spotting days) with continuous use of NET COC than with continuous use of LNG COC. The authors noted that the study findings did not support use of higher EE doses to prevent breakthrough bleeding during continuous COC use. It is not known how bleeding patterns with continuous use of other COC would compare.

Tailored regimens and HFI-associated symptoms [CoSRH, 2023a]

• A Cochrane Review of RCTs identified studies that reported improvement in menstrual-related headache, bloating, tiredness and menstrual pain with extended COC regimens.
• Observational studies similarly suggest benefit. 
  • A cohort study of 111 women who reported cyclical symptoms with two cycles of use of a 21/7 COC regimen found that mood, headache and pelvic pain scores improved significantly after the women switched to an extended COC regimen and were followed up for a year — 80% of the women continued the extended regimen for the full year, and 6 months after that most women reported that they had continued the extended regimen on their own.
  • A prospective cohort study of 109 women given 30 micrograms EE/DRSP COC for two 21/7 cycles, followed by two 84/7 cycles (two-thirds completed all cycles) reported a significantly reduced incidence of heavy menstrual bleeding (HMB), intermenstrual bleeding, dysmenorrhoea, abdominal bloating, depressed mood and irritability at the end of the second 84/7 cycle compared to at enrolment.

Return to fertility after tailored regimens [CoSRH, 2023a]

• One study found that of 187 women aged 18–49 years who had used continuous 20 micrograms EE/ LNG COC for at least 6 months, 98.9% returned to spontaneous menstruation or became pregnant within 90 days. In another study, amongst 47 women who had used 20 micrograms EE/LNG COC continuously for 84 days, ovulation was observed within 37 days of stopping treatment in all but one case (98%).

Basis for recommendation

This information is based on the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guideline Combined hormonal contraception [CoSRH, 2023a].

Basis for recommendation

This information is based on the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guideline Combined hormonal contraception [CoSRH, 2023a] and a National Institute for Health and Care Excellence (NICE) new medicine evidence summary Combined oral contraception: nomegestrol/estradiol (Zoely) [NICE, 2013].

How should I manage unscheduled bleeding in a woman using the combined oral contraceptive?

• Exclude and/or manage:
  • Situations which could compromise the effectiveness of the COC, such as missed pills, drug interactions, and vomiting or diarrhoea.
  • Situations that could result in unscheduled bleeding, such as:
    • Sexually transmitted infections (STIs) — as a minimum, test for Chlamydia trachomatis. The risk of STIs is increased if the woman is under 25 years of age, has a new sexual partner, or has had more than one sexual partner in the last year. For more information, see the CKS topic on Chlamydia - uncomplicated genital.
    • Pregnancy — perform a pregnancy test.
    • Gynaecological conditions such as cervical cancer — if this is suspected, implement an urgent suspected cancer pathway referral. For more information, see the CKS topic on Gynaecological cancers - recognition and referral.
    • Endometrial cancer — refer women aged 45 and older using a suspected refer via an urgent suspected cancer pathway referral if they have unscheduled bleeding. Refer women younger than 45 years if they have risk factors for endometrial cancer and persistent, problematic bleeding after the first 3 months of use, or if they present with a change in bleeding pattern after at least 3 months of use. For more information, see the CKS topic on Gynaecological cancers - recognition and referral.
• Consider performing a speculum and pelvic examination:
  • For persistent bleeding beyond the first 3 months of use — unscheduled bleeding is common in the first 3 months of starting a new hormonal contraceptive method.
  • For new symptoms or a change in bleeding after at least 3 months of use.
  • If the woman has not participated in the NHS Cervical Screening programme regularly. For more information, see the CKS topic on Cervical cancer and HPV.
  • If requested by the woman.
  • If there are other symptoms such as pelvic pain, dyspareunia, or post-coital bleeding. 
• If no other underlying cause of irregular bleeding is suspected, and speculum and pelvic examination is normal, the bleeding can be assumed to be caused by the COC. Providing the woman has no other symptoms:
  • Reassure her that unscheduled bleeding is common in COC users.
  • Encourage new users of the COC to persevere with use for up to 3 months.
  • If bleeding does not settle, consider one of the following options:
    • Change to a different COC (with a higher dose of oestrogen, or higher dose of progestogen, or different type of progestogen).
    • Change to another form of contraception — there may be less unscheduled bleeding with the combined vaginal ring.

Basis for recommendation

These recommendations are largely based on the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guidelines Combined hormonal contraception [CoSRH, 2023a] and Problematic bleeding with hormonal contraception [CoSRH, 2015], the National Institute for Health and Care Excellence (NICE) guideline Suspected cancer: recognition and referral [NICE, 2023], information in the British National Formulary (BNF) [BNF, 2024], and the manufacturer's Summary of Product Characteristics for Microgynon^® [EMC, 2023b].

Endometrial cancer

• NICE advises considering using an urgent suspected cancer pathway referral for women aged under 55 years with post-menopausal bleeding. However, the FSRH advises that an endometrial biopsy should be considered in women aged 45 years or over and in women under 45 years with risk factors for endometrial cancer who have persistent problematic bleeding after the first 3 months of use of a method or who present with a change in bleeding pattern [CoSRH, 2015; NICE, 2023].

Other adverse effects

• The information on combined oral contraception and mood changes, liver disease, meningioma, and angioedema derives from the relevant manufacturers' Summaries of Product Characteristics (SPCs) [EMC, 2022b; EMC, 2022c; EMC, 2023b; EMC, 2023c; EMC, 2023d].

Liver enzyme-inducing drugs

• Examples of liver enzyme-inducing drugs are:
  • Antibiotics — rifampicin and rifabutin are very potent enzyme inducers.
  • Antiseizure medications such as carbamazepine, oxcarbazepine, phenobarbital, phenytoin, primidone, and topiramate.
    • Topiramate is a suspected teratogen and can impair the effectiveness of hormonal contraceptives. Before initiating topiramate in a woman of childbearing potential, pregnancy testing should be performed. The woman should be fully informed of the risks related to the use of topiramate during pregnancy. Ensure that women and girls of childbearing potential are advised that they should be using a highly effective method of contraception.
  • Antiretrovirals such as ritonavir, ritonavir-boosted protease inhibitors, efavirenz, and nevirapine.
  • St John's wort.
    • Advise women taking a COC not to take herbal products containing St John’s wort.
• If a woman is being treated with a liver enzyme-inducing drug:
  • Advise that the efficacy of the combined oral contraceptive (COC) pill could be reduced and that effective alternative contraception should ideally be used during treatment with the enzyme-inducing drug and for 28 days afterwards.
    • Always advise the use of an alternative effective contraceptive for women taking rifampicin or rifabutin. 
    • For women taking other enzyme-inducing drugs, if an alternative effective contraceptive is not suitable, advise the concurrent use of two COC pills containing at least 50 micrograms of ethinylestradiol (for example taking both a 20 microgram and a 30 microgram COC or two 30 microgram COCs), using a continuous regimen, or tricycled with a pill-free interval of 4 days. Women should be made aware that contraceptive effectiveness is not guaranteed using these regimens, and that thrombotic risk may be increased. Advise the woman to seek urgent follow up if she experiences breakthrough bleeding, as this could indicate low serum ethinylestradiol.
    • Women taking a liver enzyme-inducing drug for less than two months can also consider continuing their usual COC alongside the reliable use of condoms, during treatment and for 28 days afterwards.
  • Consider the need for emergency contraception if sexual intercourse has taken place while the efficacy of the COC may have been reduced, for example if the woman has already started treatment with a liver enzyme-inducing drug. See the CKS topic on Contraception - emergency for more information.

Lamotrigine

• If the woman is taking lamotrigine monotherapy, advise her to change to an alternative method of contraception, as concurrent use with the combined oral contraceptive (COC) may reduce seizure control.
• If the woman still wishes to use the COC:
• Seek specialist advice, as the maintenance dose of lamotrigine may need to be increased as much as two-fold according to clinical response, and serum lamotrigine levels should be monitored.
• A continuous COC regimen should be used to avoid lamotrigine toxicity during the hormone-free interval.
• Advise the woman to seek medical advice before stopping the COC.
• The maintenance dose of lamotrigine may need to be decreased by as much as 50% if the COC is stopped, according to clinical response and lamotrigine adverse effects,
• If the woman is taking lamotrigine plus sodium valproate, the COC may not affect seizure control.
• If the woman is taking lamotrigine plus an antiseizure medication that induces liver enzymes (such as carbamazepine), follow the advice in the section on Liver enzyme-inducing drugs.

Griseofulvin

If a woman is taking griseofulvin, advise that:

• There is a possibility of reduced efficacy of the combined oral contraceptive (COC) pill.
• Griseofulvin has been associated with birth defects in animal models. Very limited human data are more reassuring, but teratogenicity cannot be ruled out until further information is available. 
• Condoms should therefore be used reliably in addition to the COC pill while taking griseofulvin and for 28 days after treatment cessation.

Additional drug interactions

• The following additional drug interactions may occur with combined oral contraceptives (COCs):
  • Orlistat — advise women on what to do if they experience diarrhoea while taking orlistat.
  • Colesevelam — decreases blood concentrations of the COC by binding to COCs in the gut and reducing absorption.
    • Advise women to take the COC 4 hours before taking colesevelam.
  • Ulipristal acetate — may reduce the efficacy of progestogen-containing contraceptives. The manufacturers of Esmya® (ulipristal acetate 5 mg) advise avoiding concomitant use.
  • Antihypertensives — the hypotensive effect may be antagonized. 
    • Monitor blood pressure, and adjust the dose of antihypertensive medication accordingly.
  • Antidiabetic drugs — oestrogens and progestogens antagonize the hypoglycaemic effect. 
    • Monitor blood glucose.
  • Antifungals (such as fluconazole, itraconazole, ketoconazole, voriconazole) — modest increase in plasma levels of oestrogens and/or progestogens. Possible increased risk of adverse effects.
  • Drugs to treat hepatitis C — the combination of hormonal contraceptives containing ethinylestradiol and products containing ombitasvir/paritaprevir/ritonavir (Viekirax) and dasabuvir with or without ribavirin, may increase the risk of ALT elevations.
  • Erythromycin — modest to marked increase in plasma levels of oestrogens and/or progestogens. Possible increased risk of adverse effects.
  • Etoricoxib —oestrogen levels increased by around 40% with etoricoxib doses of 60 mg or more. Increased risk of adverse effects.
  • Statins — minor to modest increase in plasma levels of oestrogens and/or progestogens. Not likely to be clinically significant. 
  • Diuretics — oestrogens may antagonize the diuretic effect. The dose of diuretic may need to be adjusted.
  • Levothyroxine — oestrogens may increase the requirements for thyroid hormones. 
    • Monitor thyroid function, and adjust the dose of levothyroxine accordingly.
  • Theophylline — oestrogens reduce the excretion of theophylline. 
    • The theophylline dose may need to be reduced.
  • Selegiline — oestrogens and progestogens may increase plasma levels of selegiline, leading to increased risk of toxicity. Avoid concomitant use.
  • Tacrolimus — oestrogens, norethisterone enantate, and gestodene may increase tacrolimus levels. 
    • Monitor serum tacrolimus levels. 
  • Retinoids — the adverse effect of COCs on lipid levels may be additive with isotretinoin. 
    • Monitor lipid levels. 
  • Triptans — COCs appear to modestly raise the levels of frovatriptan, naratriptan, and zolmitriptan and slightly increase levels of sumatriptan. 
    • Combined hormonal contraceptives should not be used in women who have migraine with aura.
  • Tirzepatide — Delayed gastric emptying for tirzepatide may have a greater impact on the absorption of oral contraceptives compared to other GLP-1RA medicines. However, due to limited information available about the effect of tirzepatide on the pharmacokinetics and efficacy of oral contraceptives in individuals with obesity or who are overweight, reduced efficacy cannot be excluded.
    • Since this reduced efficacy of oral contraceptives cannot be excluded, it is advised that people taking tirzepatide should switch to a non-oral contraceptive method or add a barrier method of contraception when the drug is started (for 4 weeks) and after each dose escalation (for 4 weeks).
    • No dose adjustment of oral contraceptives is required in women with a normal BMI.

Basis for recommendation

These recommendations are largely based on the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guidelines Combined hormonal contraception [CoSRH, 2023a] and Drug interactions with hormonal contraception [CoSRH, 2022], as well as the relevant manufacturers' Summaries of Product Characteristics [EMC, 2021; EMC, 2022a; EMC, 2023b; EMC, 2023a; EMC, 2024a].

Use of liver enzyme-inducing drugs

• An effective alternative contraceptive to a COC should always be advised with use of rifampicin or rifabutin, as these are potent liver enzyme inducers.
• Where a COC is continued alongside an enzyme inducer, an extended or continuous regimen is recommended, as reducing the number and length of hormone-free intervals means that there is less opportunity for ovulation and follicular development.

[CoSRH, 2022]

Breakthough bleeding

• Breakthrough bleeding when continuing COC with an enzyme-inducing drug can indicate reduced serum ethinylestradiol levels. The FSRH advises that the dose of ethinylestradiol can exceptionally be increased to a maximum of 70 micrograms after seeking specialist advice [CoSRH, 2023a].  

Griseofulvin

• Griseofulvin teratogenicity has been observed in animal models at doses higher than the human equivalent.  Data on griseofulvin use in human pregnancy do not prove teratogenic effects, but are too limited to rule these out [Reprotox, 2024; TERIS, 2024]. 
• There are case reports of contraceptive failure and menstrual irregularities in women taking oral contraceptives who were using griseofulvin [Reprotox, 2024].
• As a precaution, the FSRH therefore recommends reliable use of condoms in addition to a COC during treatment with griseofulvin [CoSRH, 2022] and the manufacturer of griseofulvin recommends that additional contraceptive measures are continued for a month following treatment cessation [EMC, 2024b].

Basis for recommendation

These recommendations are based on the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guideline UK Medical Eligibility Criteria for contraceptive use [CoSRH, 2016].

How long should the combined oral contraceptive pill be used for?

• Stop the combined oral contraceptive (COC) at 50 years of age, and switch to one of the following contraceptive methods:
  • A non-hormonal method such as the copper intrauterine device (Cu-IUD).
  • The progestogen-only pill (POP), progestogen-only implant, or the levonorgestrel intrauterine system (LNG-IUS). For more information, see the CKS topics on Contraception - IUS/IUD and Contraception - progestogen-only methods.

Basis for recommendation

These recommendations are based on the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guidelines Combined hormonal contraception [CoSRH, 2023a], Contraception for women aged over 40 years [CoSRH, 2023c], the UK Medical Eligibility Criteria for contraceptive use [CoSRH, 2016], and expert opinion in a medical textbook, Contraception today [Guillebaud, 2016].

What advice should I give a woman who has missed pills of combined oral contraceptives (COC), except Qlaira® and Zoely®?

These missed pill rules apply to all combined oral contraceptives (COCs) except Qlaira^® and Zoely^®.

• If it has been 9 completed days or more since the last active pill was taken when restarting the pill after the hormone-free interval (HFI), consider emergency contraception if unprotected sexual intercourse (UPSI) has taken place during or after the HFI, and advise the woman to:
  • Take the missed pill as soon as possible.
  • Continue taking the remaining pills at the usual time.
  • Avoid sexual intercourse or use a barrier method of contraception (such as condoms) until 7 consecutive pills have been taken. 
  • Consider a follow up pregnancy test.
• If one pill has been missed (48 to 72 hours since the last pill in the current pack was taken) on week 1 after HFI, advise the woman:
  • That emergency contraception is not required if there was consistent, correct use earlier in week 1 and the 7 days prior to HFI.
  • To take the missed pill as soon as possible.
  • To continue taking the remaining pills at the usual time. This may mean taking two pills in 24 hours (the missed pill and the next one at the usual time).
  • That no additional contraceptive precautions are required if there was consistent, correct use earlier in week 1 and the 7 days prior to HFI.
• If one pill has been missed (48 to 72 hours since the last pill in the current pack was taken) on week 2 or 3 after HFI (or subsequent consecutive weeks of continuous pill-taking), advise the woman:
  • That emergency contraception is not required if there was consistent, correct use in the previous 7 days.
  • To take the missed pill as soon as possible.
  • To continue taking the remaining pills at the usual time. This may mean taking two pills in 24 hours (the missed pill and the next one at the usual time).
  • That no additional contraceptive precautions are required if there was consistent, correct use in the previous 7 days.
• If 2–7 pills have been missed (72 hours or more since the last pill in the current pack was taken) in week 1 after HFI, consider emergency contraception if UPSI has taken place during the HFI or week 1, advise the woman to:
  • Take the most recent missed pill as soon as possible.
  • Continue taking the remaining pills at the usual time. This may mean taking two pills in 24 hours (the most recent missed pill and the next one at the usual time).
  • Use a barrier method of contraception (such as condoms) until 7 consecutive pills have been taken. 
  • Consider a follow up pregnancy test.
• If 2–7 pills have been missed (72 hours or more since the last pill in the current pack was taken) in week 2 or 3 after HFI (or subsequent consecutive weeks continuous pill-taking), advise the woman:
  • That emergency contraception is not required if there was consistent, correct use in the previous 7 days.
  • To take the most recent missed pill as soon as possible. Any earlier missed pills should be ignored.
  • To continue taking the remaining pills at the usual time. This may mean taking two pills in 24 hours (the most recent missed pill and the next one at the usual time).
  • That if there were two or more missed pills in the 7 days prior to scheduled HFI, to omit the HFI.   
  • To use a barrier method of contraception (such as condoms) until 7 consecutive pills have been taken. 
    • This is overcautious, but is a back-up in case of subsequent incorrect use. 
• If more than 7 consecutive COC pills have been missed in any week of pill-taking, consider emergency contraception. Advise the woman to:
  • Restart the COC as a new user. See the section on When can a woman start using a combined oral contraceptive? for more information.
  • Consider an immediate pregnancy test.
  • Quick start a new COC pack (or consider other effective contraception).
  • Use a barrier method of contraception (such as condoms) until 7 consecutive pills have been taken.
  • Consider a follow up pregnancy test.

What advice should I give a woman who has missed pills of Qlaira®

• If a pill is taken less than 12 hours late, advise the woman:
  • To take the missed pill immediately.
  • To take further pills at the usual time.
  • That additional contraception is not required.
• If a pill is taken more than 12 hours late, management will depend on the day of the cycle on which it has been missed. If the missed pill occurs in:
  • Days 1–17, advise the woman to:
    • Take the missed pill immediately and the next pill as usual (even if this means taking 2 pills on the same day).
    • Continue with pill taking in the normal way.
    • Use an additional contraceptive method (such as condoms) for 9 days.
  • Days 18–24, advise the woman to:
    • Discard the current packet.
    • Start immediately with the first pill of a new packet.
    • Continue pill taking in the normal way.
    • Use an additional contraceptive method (such as condoms) for 9 days.
  • Days 25–26, advise the woman to:
    • Take the missed pill immediately and the next pill at the usual time (even if it means taking two tablets on the same day). Additional contraception is not required.
  • Days 27–28 (inactive pills), advise the woman to:
    • Discard the forgotten pill and continue pill taking in the normal way. Additional contraception is not required.
• Also advise the woman that:
  • No more than 2 pills should be taken in any 1 day.
  • If pills have been missed and no withdrawal bleed occurs at the end of the packet, she should consider the possibility of pregnancy.

What advice should I give a woman who has missed pills of Zoely®

• If a pill is taken less than 24 hours late, advise the woman:
  • To take the missed pill immediately.
  • To take further pills at the usual time.
  • That additional contraception is not required.
• If a pill is taken more than 24 hours late, management will depend on the day of the cycle on which it has been missed. If the missed pill occurs in:
  • Days 1–7, advise the woman:
    • To take the missed pill immediately and the next pill as usual (even if this means taking 2 pills on the same day).
    • To continue with pill taking in the normal way.
    • To use an additional contraceptive method (such as condoms) for 7 days.
    • That if unprotected sexual intercourse (UPSI) occurred in the previous 7 days, the possibility of pregnancy should be considered.
  • Days 8–17, advise the woman:
    • To take the missed pill immediately and the next pill as usual (even if this means taking 2 pills on the same day).
    • To continue with pill taking in the normal way.
    • That no extra contraception is required provided that the 7 preceding pills have been taken correctly.
      • If more than 1 pill has been missed the woman should abstain use an additional contraceptive method (such as condoms) until she has completed 7 days of uninterrupted white tablet-taking.
    • That if no withdrawal bleed occurs at the end of the packet, the possibility of pregnancy should be considered.
  • Days 18–24, consider one of the following two options:
    • Advise the woman to take the missed pill immediately and the next pill at the usual time (even if it means taking 2 tablets on the same day); continue with the active pills in the normal way (pills are active from day 1–24); discard the inactive pills (days 25–28) and instead, start the next packet of pills. A withdrawal bleed is likely to be absent.
    • Advise the woman to discard the remainder of the active pills in the current pack and take a maximum of 3 inactive pills (so that the total number of inactive plus missed pills is no more than 4) in the normal way, then start the next packet of pills. If no withdrawal bleed occurs, the possibility of pregnancy should be considered.
  • Days 25–28 (inactive pills), advise the woman to:
    • Discard the forgotten pill and continue pill taking in the normal way. Additional contraception is not required.

Basis for recommendation

These recommendations are based on the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guidelines Recommended actions after incorrect use of combined hormonal contraception [CoSRH, 2021], Combined hormonal contraception [CoSRH, 2023a], and the relevant manufacturers' Summaries of Product Characteristics [EMC, 2022a; EMC, 2023a].

How should I assess a woman who is considering using the combined transdermal patch?

• For information on assessing a woman who is considering using the combined transdermal patch, see the section on combined transdermal patch in the CKS topic on Contraception - assessment.

When should a woman start the combined transdermal patch?

Specific advice for women who are amenorrhoeic, postpartum, post-termination, or post-miscarriage is summarized in the section Amenorrhoea, postpartum, termination of pregnancy, or miscarriage.

• If the woman is not currently using a regular method of contraception or using a barrier method (such as condoms):
  • Start the combined transdermal patch (CTP) on day 1–5 of the menstrual cycle. 
    • No additional contraception is required.
  • If the CTP is started at any other time in the menstrual cycle, provided a barrier method has been used consistently and correctly and it is reasonably certain that the woman is not pregnant:
    • Advise the woman to use a barrier method of contraception (such as condoms) for the first 7 days.
  • If pregnancy cannot be excluded and the woman wishes to start hormonal contraception without delay:
    • Prescribe the CTP and advise the woman to take a pregnancy test no sooner than 3 weeks after the last episode of unprotected sex.
• If the woman is starting after oral emergency contraception:
  • For levonorgestrel, advise the woman to start the CTP immediately and use a barrier method of contraception (such as condoms) for the first 7 days.
  • For ulipristal acetate, advise the woman to start the CTP 5 days after taking ulipristal acetate, and to use a barrier method of contraception (such as condoms) during this time and the following 7 days.
• If the woman is switching from a combined oral contraceptive (COC) or combined vaginal ring (CVR):
  • Start the CTP on the day after the last active COC, or vaginal ring. There is no need to wait for the next menstrual period. 
    • No additional contraception is required.
  • If the woman decides to take a 7-day hormone-free interval (or a 4-day hormone-free interval for Zoely^®) before starting the new CTP, assess the need for additional contraception and emergency contraception. See the CKS topic on Contraception - emergency.
• If the woman is switching from a progestogen-only pill (except desogestrel) or the levonorgestrel intrauterine system (LNG-IUS):
  • Start the CTP at any time in the menstrual cycle provided it is reasonably certain that the woman is not pregnant. 
    • There is no need to wait for the next menstrual period.
  • Advise the woman to use a barrier method of contraception (such as condoms) for the first 7 days.
• If the woman is switching from progestogen-only injectable, or desogestrel-only pill:
  • Start the CTP at any time up to when the repeat of injectable is due, or the next day after the pill.  
    • No additional contraception is required.
• If the woman is switching from the drospirenone progestogen-only pill:
  • During HFI (placebo pills, days 25–28) or days 1–7 (active pills) after HFI and no UPSI since start of HFI — start immediately and advise the woman to use a barrier method of contraception (such as condoms) for 7 days.
  • During HFI (placebo pills, days 25–28) or days 1–7 (active pills) after HFI and UPSI since start of HFI — restart/continue drospirenone until 7 consecutive pills taken then switch as for days 8–24
  • Days 8-24 (active pills) — start immediately. No additional precautions required. 
• If the woman is switching from a progestogen-only implant that has been in situ:
  • For 3 years or less — advise the woman to start the CTP immediately and that no additional contraception is required.
  • For 3 to 4 years  — rule out pregnancy and advise the woman to start the CTP immediately and use a barrier method of contraception (such as condoms) for the first 7 days. Advise the woman to take a pregnancy test 21 days following last UPSI (if applicable).
  • For more than 4 years and has not had unprotected sexual intercourse (UPSI) within the last 3 weeks  — rule out pregnancy and advise the woman to start the CTP immediately and use a barrier method of contraception (such as condoms) for the first 7 days.
  • For more than 4 years and has had UPSI within the last 3 weeks — consider the need for emergency contraception [See the CKS topic on Contraception - emergency for more information]. Otherwise, rule out pregnancy and advise the woman to start the CTP immediately and use a barrier method of contraception (such as condoms) for the first 7 days, and take a pregnancy test at 21 days following UPSI. 
• If the woman is switching from a copper intrauterine device (Cu-IUD):
  • Remove the Cu-IUD on day 1–5 of the menstrual cycle and start the CTP on the same day.
    • No additional contraception is required.
  • If the Cu-IUD is removed at any other time in the menstrual cycle: 
    • Advise the woman to use a barrier method of contraception (such as condoms) for the first 7 days.
  • If the CTP is started 7 days before removal of the Cu-IUD:
    • No additional contraception is required.

What types of combined transdermal patch are available?

• The Evra^® patch is currently the only licensed contraceptive patch available in the UK.
• It delivers 203 micrograms of norelgestromin (a progestogen) and 33.9 micrograms of ethinylestradiol (an oestrogen) into the systemic circulation over 24 hours for 7 days.
• Prescribe up to 12 months’ supply for women who are initiating or continuing CHC.

Amenorrhoea, postpartum, termination of pregnancy, or miscarriage

• If the woman is amenorrhoeic:
  • Start the CTP at any time if it is reasonably certain that the woman is not pregnant.
    • Additional contraception is required for the next 7 days.
• If the woman is postpartum and not breastfeeding:
  • Start the CTP on day 21 postpartum if no additional risk factors for venous thromboembolism exist (off-label use).
    • Additional contraception is required for 7 days.
  • If it has been more than 21 days postpartum and menstrual cycles have returned, start the CTP as for women having menstrual cycles.
  • If it has been more than 21 days postpartum and menstrual cycles have not returned, start the CTP as for women who are amenorrhoeic.
• If the woman is postpartum and breastfeeding:
  • Do not start the CTP if the woman is less than 6 weeks postpartum.
  • After 6 weeks and before 6 months postpartum, start the CTP as for women who are postpartum and not breastfeeding.
• If the woman has had a miscarriage or termination of pregnancy:
  • Start the CTP within 5 days of surgical or first stage of medical termination (ideally on day 1 or day 2). No additional contraception is required.  
    • If the CTP is applied later, provided it is reasonably certain that the woman is not pregnant, advise her to use a barrier method of contraception (such as condoms) for 7 days. 
    • Note: If gestation is 24 weeks or more, start the CTP as for a woman who is postpartum.

Basis for recommendation

Types of patch

• This information is based on the manufacturer's Summary of Product Characteristics [EMC, 2023e].

When to start

• This information is based on the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guidelines Combined hormonal contraception [CoSRH, 2023a], Contraception after pregnancy [CoSRH, 2020], and Switching or starting methods of contraception [CoSRH, 2023b], the Royal College of Obstetricians and Gynaecologists (RCOG) guideline Best practice in post-abortion contraception [RCOG, 2022], the UK Medical Eligibility Criteria for contraceptive use [CoSRH, 2016], and the manufacturer's Summary of Product Characteristics [EMC, 2023e].
• The manufacturer of Evra^® advises that if the patch is applied after day 1 of the menstrual cycle, additional contraceptive measures are needed for the following 7 days [EMC, 2023e].
  • However the FSRH Clinical Effectiveness Unit (CEU) has extrapolated the evidence for combined oral contraceptives (COCs) and advises that no additional contraception is required if the patch is started on days 2–5 of the menstrual cycle [CoSRH, 2023a].
• The manufacturer of Evra^® advises starting the patch no sooner than 4 weeks postpartum in women who are not breastfeeding [EMC, 2023e].
  • However, the FSRH has extrapolated the evidence for COCs and advises that the patch can be started after 3 weeks postpartum [CoSRH, 2016].

What advice should I provide on using the combined transdermal patch?

• Advise the woman that:
  • Only one patch should be worn at a time.
  • The patch should be applied to clean, dry, lotion-free, healthy, hairless skin.
    • Suitable patch sites are the upper outer arm, upper torso (excluding breast), buttock, or lower abdomen.
    • The patch should not be applied to red, broken, or inflamed skin.
    • To prevent interference with the adhesive properties of the patch, the woman should not apply make-up, creams, lotions, powders, or other topical products to the skin area where the patch is placed.
  • The patch is very adherent and can be used in the shower, bath, sauna, hot tub, and during exercise (including swimming).
  • She should check the patch daily to make sure it is not detached.
• To use the patch, advise the woman:
  • To apply a patch on the same day each week for 3 consecutive weeks (days 1, 8, and 15), have a patch-free interval on week 4 (days 22–28), unless using a tailored regimen, then start a new cycle.
    • The woman may (or may not) experience a withdrawal bleed in week 4.
    • Bleeding may start on any day in the patch-free week, is usually lighter and less painful than a normal period, and may continue after the patch-free week.
    • Advise the woman to start the new cycle even if she is still bleeding.
  • To use a different site when changing a patch in order to avoid skin irritation.
  • That used patches should be placed in the disposal sachets provided and put in the bin (not flushed down the toilet).

What advice should I provide if a patch becomes detached?

• A partially detached combined transdermal patch is treated the same as one that has become completely detached.
• If there has been unscheduled patch detachment for less than 48 hours, or continued use of the same patch for up to 48 additional hours in week 1 after the hormone-free interval (HFI), advise the woman:
  • That emergency contraception is not required if the patch was used correctly earlier in week 1 and the 7 days prior to the HFI.
  • To put on a new patch as soon as possible.
  • To keep the new patch on until the scheduled removal day. 
  • That no additional contraception is required if the patch was used correctly earlier in week 1 and the 7 days prior to the HFI.
• If there has been unscheduled patch detachment for less than 48 hours, or continued use of the same patch for up to 48 additional hours in week 2 or 3 after HFI (or a subsequent week of correct consecutive patch use in an extended regimen), advise the woman:
  • That emergency contraception is not required if the patch was used correctly in the previous 7 days.
  • To put on a new patch as soon as possible.
  • To keep the new patch on until the scheduled removal day. 
  • That no additional contraception is required provided the patch was worn correctly in the previous 7 days. 
• If there has been an unscheduled patch detachment for 48 hours or more, or continued use of the same patch for 48 additional hours or more in week 1 after HFI, consider emergency contraception if unprotected sexual intercourse (UPSI) has taken place during the HFI, or week 1, and advise the woman to:
  • Attach a new patch as soon as possible.
  • Keep the new patch on until the scheduled removal day.
  • Use a barrier method of contraception (such as condoms) until the new patch has been used for 7 consecutive days.
  • Consider a follow up pregnancy test.
• If there has been an unscheduled patch detachment for 48 hours or more, or continued use of the same patch for 48 additional hours or more in week 2 or 3 after HFI, (or during a subsequent week of correct consecutive patch use in an extended regimen) advise the woman:
  • That emergency contraception is not required if the patches were used correctly in the previous 7 days.
  • To attach a new patch as soon as possible and keep it on until the scheduled removal day.
  • That if the unscheduled removal occurred in the week prior to a scheduled HFI, omit the HFI. 
  • To use a barrier method of contraception (such as condoms) until the new patch has been used for 7 consecutive days.
    • This may not be necessary in the second and third weeks, but the advice is a backup in the event that unscheduled detachment occurs.

Does vomiting or diarrhoea affect the contraceptive effect of the combined transdermal patch?

• Vomiting and diarrhoea do not affect the bioavailability of the combined transdermal patch (CTP).
• No additional contraception (such as condoms) is needed if a woman vomits or has diarrhoea whilst using the CTP.

How should I manage a woman who becomes pregnant whilst using the combined transdermal patch?

• If a woman becomes pregnant whilst using the combined transdermal patch (CTP):
• Advise her to stop the patch immediately. 
• Inform her that there is no evidence of harm to the baby or the mother if pregnancy occurs while using the CTP.

What advice should I provide if a patch is not changed in time?

• If it has been 8 completed days or more since the last patch was removed for the scheduled hormone-free interval (HFI), consider emergency contraception if unprotected sexual intercourse (UPSI) has taken place during or after the HFI. Advise the woman to:
  • Attach a new patch as soon as possible.
  • Keep the new patch on until the scheduled removal day.
  • Avoid UPSI or use a barrier method of contraception (such as condoms) until the new patch has been used for 7 consecutive days.
  • Consider a follow up pregnancy test.

Basis for recommendation

These recommendations are largely based on the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guidelines Recommended actions after incorrect use of combined hormonal contraception [CoSRH, 2021], and Combined hormonal contraception [CoSRH, 2023a], ans well as the relevant manufacturer's Summary of Product Characteristics [EMC, 2023e].

Pregnancy

• These recommendations are based on the Faculty of Sexual and Reproductive Healthcare (FSRH) UK Medical Eligibility Criteria for contraceptive use [CoSRH, 2016] and the manufacturer's Summary of Product Characteristics [EMC, 2023e].

Advice about tailored CHC regimens

• The traditional 21/7 CHC regimen with a monthly withdrawal bleed confers no health benefit over other patterns of CHC use. Symptoms associated with the hormone-free interval (HFI) can be problematic and ovarian activity during a 7-day HFI could risk escape ovulation (particularly with lower doses of EE and if use is not perfect). Tailored CHC regimens can be safely used to avoid withdrawal bleeds and associated symptoms and theoretically reduce the risk of contraceptive failure. 

Safety of tailored regimens

• Direct data comparing risk of cardiovascular events and cancer between extended and standard CHC regimens are lacking, however, the FSRH states that indirect evidence regarding cardiovascular risk is reassuring.
  • In a Phase 3 trial of 20 micrograms ethinylestradiol/drospirenone (EE/DRSP) combined oral contraceptive (COC), 1067 women were randomised to standard cyclical, flexible extended or fixed extended pill-taking regimens for 1 year. A total of 755 women then entered an extension phase, taking the flexible extended regimen. Metabolic and haemostatic parameters, serum hormone levels and blood pressure were similar in all groups. Numbers of serious adverse events were very low in all groups.
  • A smaller trial which randomised 78 women to use extended or standard cyclical regimens of 30 micrograms EE/DRSP COC found no statistically significant differences in carbohydrate or lipid profiles between the two groups over 6 months of use.
  • In a third trial, 174 women were randomised to cyclical or continuous use of 20 micrograms EE/levonorgestrel (LNG) COC (the dose of LNG was different in the two groups). The authors concluded that after 13 months of use, carbohydrate metabolism, lipid profile and haemostatic variables were broadly similar between the groups, but that further studies would be required to assess long-term continuous CHC. Haemostatic parameters were reported to be similar for 187 women randomised to extended or cyclical use of 30 micrograms EE/LNG COC for 6 months.
• Limited information is available on the short- and long-term safety of the combined transdermal patch (CTP) and combined vaginal ring (CVR). However, after reviewing the available evidence, the FSRH guideline development group considers that recommendations for COC can be extrapolated to include CTP and CVR.

Bleeding patterns with extended CHC regimens

• A Cochrane Review of randomized controlled trials (RCTs) reported that in most studies bleeding patterns with extended CHC regimens were equivalent or improved compared to standard regimens.
• A systematic review that included both RCTs and observational studies concluded that overall, the total number of days of bleeding was lower with continuous or extended regimens than with cyclical use of CHC. However, there was an increase in breakthrough bleeding during the first months of use of continuous or extended regimens, its frequency and intensity subsequently decreased over time.
• Limited evidence suggests that bleeding patterns with continuous or extended use of the combined transdermal patch (CTP) and combined vaginal ring (CVR) show a similar reduction in bleeding/spotting days over time to that seen with extended use of COC.
• One study compared bleeding patterns in 139 existing cyclic COC users who were randomised to continuous use for 180 days of COC containing 30 micrograms EE/100 micrograms LNG, 20 micrograms EE/100 micrograms LNG, 30 micrograms EE/1000 micrograms norethisterone (NET) or 20 micrograms EE/1000 micrograms NET (only the first of these is available in the UK). The study suggested more favourable bleeding patterns (more amenorrhoea and fewer spotting days) with continuous use of NET COC than with continuous use of LNG COC. The authors noted that the study findings did not support use of higher EE doses to prevent breakthrough bleeding during continuous COC use. It is not known how bleeding patterns with continuous use of other COC would compare.

Tailored regimens and HFI-associated symptoms

• A Cochrane Review of RCTs identified studies that reported improvement in menstrual-related headache, bloating, tiredness and menstrual pain with extended COC regimens.
• Observational studies similarly suggest benefit. 
  • A cohort study of 111 women who reported cyclical symptoms with two cycles of use of a 21/7 COC regimen found that mood, headache and pelvic pain scores improved significantly after the women switched to an extended COC regimen and were followed up for a year — 80% of the women continued the extended regimen for the full year, and 6 months after that most women reported that they had continued the extended regimen on their own.
  • A prospective cohort study of 109 women given 30 micrograms EE/DRSP COC for two 21/7 cycles, followed by two 84/7 cycles (two-thirds completed all cycles) reported a significantly reduced incidence of heavy menstrual bleeding (HMB), intermenstrual bleeding, dysmenorrhoea, abdominal bloating, depressed mood and irritability at the end of the second 84/7 cycle compared to at enrolment.

Return to fertility after tailored regimens

• One study found that of 187 women aged 18–49 years who had used continuous 20 micrograms EE/ LNG COC for at least 6 months, 98.9% returned to spontaneous menstruation or became pregnant within 90 days. In another study, amongst 47 women who had used 20 micrograms EE/LNG COC continuously for 84 days, ovulation was observed within 37 days of stopping treatment in all but one case (98%).

[CoSRH, 2023a]

How should I manage unscheduled bleeding in a woman using the combined transdermal patch?

The management of unscheduled bleeding for users of the combined transdermal patch (CTP) is the same as for women taking combined oral contraceptives. For more information, see the section on unscheduled bleeding.

Basis for recommendation

These recommendations are  based on the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guidelines Combined hormonal contraception [CoSRH, 2023a] and Problematic bleeding with hormonal contraception [CoSRH, 2015], the National Institute for Health and Care Excellence (NICE) guideline Suspected cancer: recognition and referral [NICE, 2023], information in the British National Formulary (BNF) [BNF, 2024], and the manufacturer's Summary of Product Characteristics [EMC, 2023e].

Basis for recommendation

This advice is extrapolated from information about the contraceptive patch within the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guideline Combined hormonal contraception [CoSRH, 2023a], and the manufacturer's Summary of Product Characteristics [EMC, 2023e].

Basis for recommendation

This information is based on the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guideline Combined hormonal contraception [CoSRH, 2023a] and the manufacturer's Summary of Product Characteristics [EMC, 2023e].

Liver enzyme-inducing drugs

• Advise the woman that liver enzyme-inducing drugs may reduce the efficacy of the combined transdermal patch (CTP). Examples of liver enzyme-inducing drugs are:
  • Antibiotics — rifampicin and rifabutin are very potent enzyme inducers.
  • Antiseizure medications such as carbamazepine, oxcarbazepine, phenobarbital, phenytoin, primidone, and topiramate.
  • Topiramate is a suspected teratogen and can impair the effectiveness of hormonal contraceptives.
    • Before initiating topiramate in a woman of childbearing potential, pregnancy testing should be performed. The woman should be fully informed of the risks related to the use of topiramate during pregnancy. Ensure that women and girls of childbearing potential are advised that they should be using a highly effective method of contraception.
  • Antiretrovirals such as ritonavir, ritonavir-boosted protease inhibitors, efavirenz, and nevirapine.
  • St John's wort.
    • Advise women taking a CTP not to take herbal products containing St John’s wort.
• If a woman is on short-term treatment (2 months or less) with a liver enzyme-inducing drug:
  • Always advise her to change to an alternative contraceptive method if she is taking rifampicin or rifabutin. 
  • If an alternative contraceptive method is not suitable for a woman taking other enzyme-inducing drugs, advise her:
    • To continue using one patch weekly, and if she continues to take the liver enzyme-inducing drug beyond week 3, to apply the next patch and avoid the normal patch-free week.
    • To use a barrier method of contraception (such as condoms) while taking, and for 28 days after stopping, the liver enzyme-inducing drug.
    • That increasing the dose to two patches is not recommended.
  • Consider the need for emergency contraception if sexual intercourse has taken place while the efficacy of the patch may have been reduced, for example, if the woman has already started treatment with a liver enzyme-inducing drug. See the CKS topic on Contraception - emergency for more information.
• If a woman is on long-term treatment (longer than 2 months) with a liver enzyme-inducing drug:
• Advise her to change to an alternative contraceptive method unaffected by liver enzyme-inducing drugs.
• Advise her that increasing the dose to two patches is not recommended.
• Consider the need for emergency contraception if sexual intercourse has taken place while the efficacy of the patch may have been reduced, for example if the woman has already started treatment with a liver enzyme-inducing drug. See the CKS topic on Contraception - emergency for more information.

Lamotrigine

• If the woman is taking lamotrigine monotherapy, advise her to change to an alternative method of contraception, as concurrent use with the combined transdermal patch (CTP) may reduce seizure control. If the woman still wishes to use the CTP:
  • Seek specialist advice, as the maintenance dose of lamotrigine may need to be increased as much as two-fold according to clinical response, and serum lamotrigine levels should be monitored.
  • A continuous regimen should be used to avoid lamotrigine toxicity during the hormone-free interval.
  • Advise the woman to seek medical advice before stopping the CTP.
    • The maintenance dose of lamotrigine may need to be decreased by as much as 50% if the CTP is stopped, according to clinical response and lamotrigine adverse effects,
• If the woman is taking lamotrigine plus sodium valproate, the CTP may not affect seizure control.
• If the woman is taking lamotrigine plus an antiseizure medication that induces liver enzymes (such as carbamazepine), follow the advice in the section on Liver enzyme-inducing drugs.

Griseofulvin

If a woman is taking griseofulvin, advise that:

• There is a possibility of reduced efficacy of the combined transdermal patch (CTP).
• Griseofulvin has been associated with birth defects in animal models. Very limited human data are more reassuring, but teratogenicity cannot be ruled out until further information is available. 
• Condoms should therefore be used reliably in addition to the CTP while taking griseofulvin and for 28 days after treatment cessation.

Additional drug interactions

• The following drug interactions may occur with the combined transdermal patch (CTP):
  • Ulipristal acetate — may reduce the efficacy of progestogen-containing contraceptives. The manufacturers of Esmya^® (ulipristal acetate 5 mg) advise avoiding concomitant use.
  • Antihypertensives — the hypotensive effect may be antagonized. 
    • Monitor blood pressure, and adjust the dose of antihypertensive medication accordingly.
  • Antidiabetic drugs — oestrogens and progestogens antagonize the hypoglycaemic effect. 
    • Monitor blood glucose.
  • Antifungals (such as fluconazole, itraconazole, ketoconazole, and voriconazole) — modest increase in plasma levels of oestrogens and/or progestogens. Possible increased risk of adverse effects.
  • Erythromycin — modest to marked increase in plasma levels of oestrogens and/or progestogens. Possible increased risk of adverse effects.
  • Etoricoxib — oestrogen levels increased by around 40% with etoricoxib doses of 60 mg or more. Increased risk of adverse effects.
  • Statins — minor to modest increase in plasma levels of oestrogens and/or progestogens. Not likely to be clinically significant. 
  • Diuretics — oestrogens may antagonize the diuretic effect. The dose of diuretic may need to be adjusted.
  • Levothyroxine — oestrogens may increase the requirements for thyroid hormones. 
    • Monitor thyroid function, and adjust the dose of levothyroxine accordingly.
  • Theophylline — oestrogens reduce the excretion of theophylline. 
    • The theophylline dose may need to be reduced.
  • Selegiline — oestrogens and progestogens may increase plasma levels of selegiline, leading to an increased risk of toxicity. Avoid concomitant use.
  • Tacrolimus — oestrogens, norethisterone enantate, and gestodene possibly increase tacrolimus levels. 
    • Monitor serum tacrolimus levels. 
  • Retinoids — the adverse effect on lipid levels may be additive with isotretinoin. 
    • Monitor lipid levels. 
  • Triptans — combined hormonal contraceptives appear to modestly raise the levels of frovatriptan, naratriptan, and zolmitriptan and slightly increase levels of sumatriptan. 
    • Combined hormonal contraceptives should not be used in women who have migraine with aura. 

Basis for recommendation

These recommendations are largely based on the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guidelines Combined hormonal contraception [CoSRH, 2023a] and Drug interactions with hormonal contraception [CoSRH, 2022], as well as the relevant manufacturer's Summary of Product Characteristics [EMC, 2023e].

Griseofulvin

• Griseofulvin teratogenicity has been observed in animal models at doses higher than the human equivalent.  Data on griseofulvin use in human pregnancy do not prove teratogenic effects, but are too limited to rule these out [Reprotox, 2024; TERIS, 2024]. 
• There are case reports of contraceptive failure and menstrual irregularities in women taking oral contraceptives who were using griseofulvin [Reprotox, 2024].
• As a precaution, the FSRH therefore recommends reliable use of condoms in addition to a combined hormonal contraceptive during treatment with griseofulvin [CoSRH, 2022] and the manufacturer of griseofulvin recommends that additional contraceptive measures are continued for a month following treatment cessation [EMC, 2024b].

Basis for recommendation

These recommendations are based on the Faculty of Sexual and Reproductive Healthcare (FSRH) UK Medical Eligibility Criteria for contraceptive use [CoSRH, 2016].

How long should the combined transdermal patch be used for?

• Stop the combined transdermal patch at 50 years of age, and switch to one of the following contraceptive methods:
  • A non-hormonal method such as the copper intrauterine device (Cu-IUD). For more information, see the CKS topic on Contraception - IUS/IUD. 
  • The progestogen-only pill (POP), progestogen-only implant, or the levonorgestrel intrauterine system (LNG-IUS). For more information, see the CKS topics on Contraception - progestogen-only methods and Contraception - IUS/IUD.

Basis for recommendation

These recommendations are based on the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guidelines Combined hormonal contraception [CoSRH, 2023a], Contraception for women aged over 40 years [CoSRH, 2023c], the UK Medical Eligibility Criteria for contraceptive use [CoSRH, 2016], and expert opinion in a medical textbook, Contraception today [Guillebaud, 2016].

How should I assess a woman considering starting a combined vaginal ring?

• For information on assessing a woman considering starting a combined vaginal ring, see the section on combined vaginal ring in CKS topic on Contraception - assessment.

What types of combined vaginal ring are available?

• The NuvaRing^® is currently the only licensed contraceptive vaginal ring (CVR) available in the UK.
• It is a flexible, latex-free, transparent, and colourless (or almost colourless) ring, which releases etonogestrel and ethinylestradiol at an average amount of 120 micrograms and 15 micrograms respectively per 24 hours, over a period of 3 weeks.
• Prescribe up to 12 months’ supply for women who are initiating or continuing CHC.
  • However, only 3 months of NuvaRing® can be dispensed at any one time.

When can a woman start using the combined vaginal ring?

• If the woman is not currently using a regular method of contraception or using a barrier method of contraception (such as condoms):
  • Advise her to insert the combined vaginal ring (CVR) on day 1–5 of the menstrual cycle.
    • No additional contraception is required.
  • If the CVR is inserted at any other time in the menstrual cycle, provided a barrier method has been used consistently and correctly and it is reasonably certain that the woman is not pregnant:
    • Advise the woman to use a barrier method of contraception (such as condoms) for the first 7 days.
  • If pregnancy cannot be excluded and the woman wishes to start hormonal contraception without delay:
    • Advise her to insert the vaginal ring and to take a pregnancy test no sooner than 3 weeks after the last episode of unprotected sex.
• If the woman is starting immediately after oral emergency contraception:
  • For levonorgestrel, advise the woman to insert the CVR immediately and use a barrier method of contraception (such as condoms) for the first 7 days.
  • For ulipristal acetate, advise the woman to insert the CVR 5 days after taking it, and to use a barrier method of contraception (such as condoms) for this time and the next 7 days.
• If the woman is switching from the combined oral contraceptive (COC) pill or combined transdermal patch (CTP):
  • Advise the woman to insert the vaginal ring on the day after the last active COC pill or removal of the patch. There is no need to wait for the next menstrual period. 
    • No additional contraception is required.
  • If the woman decides to take a 7-day hormone-free interval (or a 4-day hormone-free interval for Zoely®) before starting the CVR, assess the need for additional contraception and emergency contraception. See the CKS topic on Contraception - emergency.
• If the woman is switching from a progestogen-only pill (except desogestrel) or a levonorgestrel intrauterine system (LNG-IUS):
  • Advise the woman to insert the CVR at any time in the menstrual cycle provided it is reasonably certain that the woman is not pregnant. 
    • There is no need to wait for the next menstrual period.
  • Advise the woman to use a barrier method of contraception (such as condoms) for 7 days after inserting the ring.
• If the woman is switching from a progestogen-only injectable, or a desogestrel-only pill:
  • Advise the woman to insert the CVR at any time up to when the repeat of injectable is due, or the next day after taking desogestrel.  
    • No additional contraception is required.
• If the woman is switching from the drospirenone progestogen-only pill:
  • During HFI (placebo pills, days 25–28) or days 1–7 (active pills) after HFI and no UPSI since start of HFI — start immediately and advise the woman to use a barrier method of contraception (such as condoms) for 7 days.
  • During HFI (placebo pills, days 25–28) or days 1–7 (active pills) after HFI and UPSI since start of HFI — restart/continue drospirenone until 7 consecutive pills taken then switch as for days 8–24.
  • Days 8-24 (active pills) — start immediately. No additional precautions required. 
• If the woman is switching from a progestogen-only implant that has been in situ:
  • For 3 years or less — advise the woman to insert the CVR immediately and that no additional contraception is required.
  • For 3 to 4 years  — rule out pregnancy and advise the woman to start the CVR immediately and use a barrier method of contraception (such as condoms) for the first 7 days. Advise the woman to take a pregnancy test 21 days following last UPSI (if applicable).
  • For more than 4 years and has not had unprotected sexual intercourse (UPSI) within the last 3 weeks  — rule out pregnancy and advise the woman to start the CVR immediately and use a barrier method of contraception (such as condoms) for the first 7 days.
  • For more than 4 years and has had UPSI within the last 3 weeks — consider the need for emergency contraception [See the CKS topic on Contraception - emergency for more information]. Otherwise, rule out pregnancy and advise the woman to start the CVR immediately and use a barrier method of contraception (such as condoms) for the first 7 days, and take a pregnancy test at 21 days following UPSI. 
• If the woman is switching from a copper intrauterine device (Cu-IUD):
  • Remove the Cu-IUD on day 1–5 of the menstrual cycle and insert the CVR on the same day.
    • No additional contraception is required.
  • If the Cu-IUD is removed at any other time in the cycle: 
    • Advise the woman to use a barrier method of contraception (such as condoms) for the first 7 days.
  • If the CVR is started 7 days before removal of the Cu-IUD:
    • No additional contraception is required.

Amenorrhoea, postpartum, termination of pregnancy, or miscarriage

• If the woman is amenorrhoeic:
  • The CVR can be inserted at any time if it is reasonably certain that the woman is not pregnant.
    • Additional contraception is required for 7 days.
• If the woman is postpartum and not breastfeeding:
  • Start the CVR on day 21 postpartum if no additional risk factors for venous thromboembolism exist.
    • Additional contraception is required for 7 days.
  • If it has been more than 21 days postpartum and menstrual cycles have returned, start the CVR as for other women having menstrual cycles.
  • If it has been more than 21 days postpartum and menstrual cycles have not returned, start the CVR as for a woman who is amenorrhoeic.
• If the woman is postpartum and breastfeeding:
  • Do not start the CVR if the woman is less than 6 weeks postpartum.
  • After 6 weeks and before 6 months postpartum, start the CVR as for women who are postpartum and not breastfeeding.
• If the woman has had a miscarriage or termination of pregnancy:
  • If gestation is less than 24 weeks, start the CVR once the pregnancy has been removed or expelled. No additional contraception is required where the CVR is inserted within 5 days of a surgical or medical abortion.
    • If the CVR is started later, provided it is reasonably certain that the woman is not pregnant, advise the woman to use a barrier method (such as condoms) for 7 days. 
  • If gestation is 24 weeks or more, start the CVR as for a woman who is postpartum.

Basis for recommendation

Types of vaginal ring

• This information is based on the manufacturer's Summary of Product Characteristics [EMC, 2022d], and information from the British National Formulary (BNF) [BNF, 2024].

When to start

These recommendations are based on the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guidelines Combined hormonal contraception [CoSRH, 2023a], Contraception after pregnancy [CoSRH, 2020], and Switching or starting methods of contraception [CoSRH, 2023b], the Royal College of Obstetricians and Gynaecologists (RCOG) guideline Best practice in post-abortion contraception [RCOG, 2022], the UK Medical Eligibility Criteria for contraceptive use [CoSRH, 2016], and the manufacturer's Summary of Product Characteristics [EMC, 2022d].

• The manufacturer of NuvaRing^® advises that if the ring is inserted on days 2–5 of the menstrual cycle, additional contraceptive measures are needed for the following 7 days [EMC, 2022d].
• However, the FSRH Clinical Effectiveness Unit (CEU) advises that no additional contraception is required if the combined vaginal ring is started on days 2–5 of the menstrual cycle [CoSRH, 2023a].

How should the combined contraceptive vaginal ring be used?

• Advise the woman:
  • To insert one ring high into the vagina for 3 weeks of continuous use per cycle. A new ring should be inserted after a 7-day ring-free break, which then starts a new cycle, unless a tailored regimen is being used.
    • To insert the ring, the woman should find a comfortable position (standing with one leg up, squatting, or lying down).
    • The ring should be compressed and inserted high into the vagina until it feels comfortable — the exact position is not critical for the ring to provide effective contraception.
  • To check the presence of the ring regularly, as it may be expelled if it is not inserted properly, while removing a tampon, during sexual intercourse, or during episodes of chronic constipation.
  • That the ring may be kept in during tampon use and sexual intercourse (but may be removed for no more than 3 hours if intercourse is uncomfortable with the ring in situ).
  • That the ring can be removed by hooking the index finger under the ring or grasping it between the index and middle finger.
  • That used rings should be placed in the disposal sachets provided and put in the bin, not flushed down the toilet.

Does vomiting or diarrhoea affect the contraceptive efficacy of the combined vaginal ring?

• Vomiting and diarrhoea do not affect the bioavailability of the combined contraceptive vaginal ring (CVR).
• No additional contraceptive measures (such as condoms) are needed if a woman vomits or has diarrhoea whilst using the CVR.

How should I manage a woman who becomes pregnant whilst using the combined vaginal ring (CVR)?

• If a woman becomes pregnant whilst using the combined vaginal ring (CVR):
  • Advise her to remove the ring.
  • Inform her that there is no evidence of increased risk of birth defects in the baby if pregnancy occurs whilst using the CVR. 

What advice should I give a woman with an expelled, removed or broken combined contraceptive vaginal ring?

• If it has been 8 or more completed days since the last ring was removed for a scheduled hormone-free interval (HFI), consider emergency contraception if unprotected sexual intercourse (UPSI) has taken place during or after HFI, and advise the woman to: 
  • Insert a new ring as soon as possible.
  • Keep the ring in until the scheduled removal day.
  • Use a barrier method of contraception (such as condoms) until the ring has been used for 7 consecutive days.
  • Consider a follow up pregnancy test.
• If the ring is removed or expelled and left outside the vagina for less than 3 hours, contraceptive efficacy is not reduced:
  • If appropriate, the ring can be rinsed in cold to lukewarm water and reinstated.
  • Otherwise, a new ring should be inserted within 3 hours.
• If the ring is removed or expelled and left outside the vagina for more than 3 hours in week 1 or 2 after HFI, consider emergency contraception if unprotected sexual intercourse (UPSI) has taken place during HFI or week 1 or 2, and advise her to: 
  • Reinsert the ring or a new ring as soon as possible.
  • Keep the ring in until the scheduled removal day.
  • Use a barrier method of contraception (such as condoms) until the ring has been used for 7 consecutive days.
  • Consider a follow up pregnancy test.
• If the ring is removed or expelled and left outside the vagina for more than 3 hours in week 3 after HFI (or a subsequent week of correct consecutive ring use in an extended regimen), advise the woman:
  • That emergency contraception is not required if the ring was used correctly in the previous 7 days.
  • To discard the expelled ring and either:
    • Omit the HFI (if applicable) and start the next 3-week use period by inserting a new ring.
    • Incorporate the ring-free time as the start of an HFI and reinstate a new ring seven days from when the ring was expelled or removed.
  • To consider use of a barrier method of contraception (such as condoms) until the new ring has been used for 7 consecutive days.
    • This is overcautious, but is a backup in case of subsequent incorrect use.
• If the ring is found to be broken, advise the woman to:
  • Remove it and reinsert a new ring as soon as possible.
  • Use a barrier method of contraception (such as condoms) for the next 7 days.
  • Consider emergency contraception if UPSI has taken place in the previous 5 days — for more information, see the CKS topic on Contraception - emergency.

What advice should I provide if the combined contraceptive vaginal ring has not been changed after 3 weeks?

• If the ring has been left in place for more than 21 days but 28 days or less, advise the woman: 
  • That emergency contraception is not required if the ring was used correctly from day 21 to 28.
  • To start the hormone-free interval (HFI) if scheduled and insert a new ring at the end of the HFI, or insert a new ring.
  • No additional contraceptive precautions are required if ring was consistently in situ from day 21 to day 28 of use.
• If the ring has been in place for more than 4 weeks or 5 weeks or less, advise the woman:
  • That emergency contraception is not required if the ring was used correctly for the last 7 days. 
  • To omit the HFI.
  • Insert a new ring as soon as possible.
  • To use a barrier method of contraception (such as condoms) until the ring has been correctly used for 7 consecutive days.
    • This is overcautious, but is a backup in case of subsequent incorrect use.
• If the ring has been in place for more than 5 weeks, consider emergency contraception if unprotected sexual intercourse (UPSI) occurred during week 5 or later. Advise the woman to:
  • Consider an immediate pregnancy test.
  • To omit the HFI.
  • Insert a new ring as soon as possible.
  • Use a barrier method of contraception (such as condoms) until the ring has been correctly used for 7 consecutive days.
  • Consider a follow up pregnancy test.
• No withdrawal bleed in the ring-free interval
  • If a woman has not used the ring as recommended, and has no withdrawal bleed in the ring-free week, exclude pregnancy and consider the need for emergency contraception before a new ring is inserted. For more information, see the CKS topic on Contraception - emergency.

Basis for recommendation

These recommendations are based on the Faculty of Sexual and Reproductive Healthcare clinical guidelines (FSRH) Combined hormonal contraception [CoSRH, 2023a], and Recommended actions after incorrect use of combined hormonal contraception [CoSRH, 2021], and the relevant manufacturer's Summary of product characteristics [EMC, 2022d].

How to use the vaginal ring

• These recommendations are based on the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guideline Combined hormonal contraception [CoSRH, 2023a], and the manufacturer's Summary of Product Characteristics [EMC, 2022d].

Vomiting and diarrhoea

• These recommendations are based on the manufacturer's Summary of Product Characteristics [EMC, 2022d].

Pregnancy

• These recommendations are based on the Faculty of Sexual and Reproductive Healthcare (FSRH) UK Medical Eligibility Criteria [CoSRH, 2016], and the manufacturer's Summary of Product Characteristics [EMC, 2022d].

Ring expelled or removed

The manufacturer of Nuvaring^® [EMC, 2022d] and the British National Formulary (BNF) [BNF, 2024] both state that contraceptive efficacy may be compromised when the ring is removed from the vagina for more than 3 hours, whereas advice from the FSRH states that additional contraceptive measures need to be considered under some circumstances when the ring has been removed for more than 48 hours [CoSRH, 2021]. CKS has chosen to cite the advice from the manufacturer on the basis that this is more cautious and therefore potentially more effective for the avoidance of unplanned pregnancy.

Advice about tailored CHC regimens

• The traditional 21/7 CHC regimen with a monthly withdrawal bleed confers no health benefit over other patterns of CHC use. Symptoms associated with the hormone-free interval (HFI) can be problematic and ovarian activity during a 7-day HFI could risk escape ovulation (particularly with lower doses of EE and if use is not perfect). Tailored CHC regimens can be safely used to avoid withdrawal bleeds and associated symptoms and theoretically reduce the risk of contraceptive failure. 

Safety of tailored regimens

• Direct data comparing risk of cardiovascular events and cancer between extended and standard CHC regimens are lacking, however, the FSRH states that indirect evidence regarding cardiovascular risk is reassuring.
  • In a Phase 3 trial of 20 micrograms ethinylestradiol/drospirenone (EE/DRSP) combined oral contraceptive (COC), 1067 women were randomised to standard cyclical, flexible extended or fixed extended pill-taking regimens for 1 year. A total of 755 women then entered an extension phase, taking the flexible extended regimen. Metabolic and haemostatic parameters, serum hormone levels and blood pressure were similar in all groups. Numbers of serious adverse events were very low in all groups.
  • A smaller trial which randomised 78 women to use extended or standard cyclical regimens of 30 micrograms EE/DRSP COC found no statistically significant differences in carbohydrate or lipid profiles between the two groups over 6 months of use.
  • In a third trial, 174 women were randomised to cyclical or continuous use of 20 micrograms EE/levonorgestrel (LNG) COC (the dose of LNG was different in the two groups). The authors concluded that after 13 months of use, carbohydrate metabolism, lipid profile and haemostatic variables were broadly similar between the groups, but that further studies would be required to assess long-term continuous CHC. Haemostatic parameters were reported to be similar for 187 women randomised to extended or cyclical use of 30 micrograms EE/LNG COC for 6 months.
• Limited information is available on the short- and long-term safety of the combined transdermal patch (CTP) and combined vaginal ring (CVR). However, after reviewing the available evidence, the FSRH guideline development group considers that recommendations for COC can be extrapolated to include CTP and CVR.

Bleeding patterns with extended CHC regimens

• A Cochrane Review of randomized controlled trials (RCTs) reported that in most studies bleeding patterns with extended CHC regimens were equivalent or improved compared to standard regimens.
• A systematic review that included both RCTs and observational studies concluded that overall, the total number of days of bleeding was lower with continuous or extended regimens than with cyclical use of CHC. However, there was an increase in breakthrough bleeding during the first months of use of continuous or extended regimens, its frequency and intensity subsequently decreased over time.
• Limited evidence suggests that bleeding patterns with continuous or extended use of the combined transdermal patch (CTP) and combined vaginal ring (CVR) show a similar reduction in bleeding/spotting days over time to that seen with extended use of COC.
• One study compared bleeding patterns in 139 existing cyclic COC users who were randomised to continuous use for 180 days of COC containing 30 micrograms EE/100 micrograms LNG, 20 micrograms EE/100 micrograms LNG, 30 micrograms EE/1000 micrograms norethisterone (NET) or 20 micrograms EE/1000 micrograms NET (only the first of these is available in the UK). The study suggested more favourable bleeding patterns (more amenorrhoea and fewer spotting days) with continuous use of NET COC than with continuous use of LNG COC. The authors noted that the study findings did not support use of higher EE doses to prevent breakthrough bleeding during continuous COC use. It is not known how bleeding patterns with continuous use of other COC would compare.

Tailored regimens and HFI-associated symptoms

• A Cochrane Review of RCTs identified studies that reported improvement in menstrual-related headache, bloating, tiredness and menstrual pain with extended COC regimens.
• Observational studies similarly suggest benefit. 
  • A cohort study of 111 women who reported cyclical symptoms with two cycles of use of a 21/7 COC regimen found that mood, headache and pelvic pain scores improved significantly after the women switched to an extended COC regimen and were followed up for a year — 80% of the women continued the extended regimen for the full year, and 6 months after that most women reported that they had continued the extended regimen on their own.
  • A prospective cohort study of 109 women given 30 micrograms EE/DRSP COC for two 21/7 cycles, followed by two 84/7 cycles (two-thirds completed all cycles) reported a significantly reduced incidence of heavy menstrual bleeding (HMB), intermenstrual bleeding, dysmenorrhoea, abdominal bloating, depressed mood and irritability at the end of the second 84/7 cycle compared to at enrolment.

Return to fertility after tailored regimens

• One study found that of 187 women aged 18–49 years who had used continuous 20 micrograms EE/ LNG COC for at least 6 months, 98.9% returned to spontaneous menstruation or became pregnant within 90 days. In another study, amongst 47 women who had used 20 micrograms EE/LNG COC continuously for 84 days, ovulation was observed within 37 days of stopping treatment in all but one case (98%).

[CoSRH, 2023a]

Basis for recommendation

This advice is extrapolated from information about the combined vaginal ring within the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guideline Combined hormonal contraception [CoSRH, 2023a], and the manufacturer's Summary of Product Characteristics [EMC, 2022d].

How should I manage a woman with unscheduled bleeding while using the combined contraceptive vaginal ring?

• The management of unscheduled bleeding for users of the combined vaginal ring (CVR) is the same as for women taking combined oral contraceptives (COCs). For more information, see the section on unscheduled bleeding.
• There may be less unscheduled bleeding with the CVR compared with COCs.

How should I manage a woman who has not had a withdrawal bleed?

• Some women using the combined vaginal ring do not experience a withdrawal bleed in the ring-free week.
  • If the ring has been used as recommended, it is unlikely the woman is pregnant.
  • If the ring has not been used as recommended prior to the first missed withdrawal bleed, or if there are two missed withdrawal bleeds, exclude pregnancy before use of the ring is continued.

Basis for recommendation

These recommendations are based on the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guidelines Combined hormonal contraception [CoSRH, 2023a] and Problematic bleeding with hormonal contraception [CoSRH, 2015], the National Institute for Health and Care Excellence (NICE) guideline Suspected cancer: recognition and referral [NICE, 2023], information in the British National Formulary (BNF) [BNF, 2024], and the manufacturer's Summary of Product Characteristics [EMC, 2022d].

Basis for recommendation

This information is based on the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guideline Combined hormonal contraception [CoSRH, 2023a]. 

Liver enzyme-inducing drugs

• Advise the woman that liver enzyme-inducing drugs may reduce the efficacy of the combined vaginal ring (CVR). Examples of liver enzyme-inducing drugs are:
  • Antibiotics — rifampicin and rifabutin are very potent enzyme inducers.
  • Antiseizure medications such as carbamazepine, oxcarbazepine, phenobarbital, phenytoin, primidone, and topiramate.
  • Topiramate is a suspected teratogen and can impair the effectiveness of hormonal contraceptives.
    • Before initiating topiramate in a woman of childbearing potential, pregnancy testing should be performed. The woman should be fully informed of the risks related to the use of topiramate during pregnancy. Ensure that women and girls of childbearing potential are advised that they should be using a highly effective method of contraception.
  • Antiretrovirals such as ritonavir, ritonavir-boosted protease inhibitors, efavirenz, and nevirapine.
  • St John's wort.
    • Advise women using a CVR not to take herbal products containing St John’s wort.

If a woman is on short-term treatment (2 months or less) with a liver enzyme-inducing drug:

• Always advise her to change to an alternative contraceptive method if she is taking rifampicin or rifabutin.
  • For example, stopping the use of the CVR and having a one-off progestogen-only injection to cover the short-term treatment and for 28 days after.
• If an alternative contraceptive method is not suitable for a woman taking other enzyme-inducing drugs, advise her:
  • To continue using the CVR, and if she continues to take the liver enzyme-inducing drug beyond week 3 of the CVR cycle, to insert the next ring, but omit the normal ring-free week.
  • To use a barrier method of contraception (such as condoms) while taking, and for 28 days after stopping, the liver enzyme-inducing drug.
  • That increasing the dose to two vaginal rings is not recommended.
• Consider the need for emergency contraception if sexual intercourse has taken place while the efficacy of the CVR may be reduced, for example if the woman has already started treatment with a liver enzyme-inducing drug. See the CKS topic on Contraception - emergency.

If a woman is on long-term treatment (longer than 2 months) with a liver enzyme-inducing drug:

• Advise her to change to an alternative contraceptive method unaffected by liver enzyme-inducing drugs.
• Advise her that increasing the dose to two vaginal rings is not recommended.
• Consider the need for emergency contraception if sexual intercourse has taken place while the efficacy of the CVR may be reduced, for example if the woman has already started treatment with a liver enzyme-inducing drug. See the CKS topic on Contraception - emergency.

Additional drug interactions

• The following drug interactions may occur with the combined vaginal ring (CVR):
  • Ulipristal acetate — may reduce the efficacy of progestogen-containing contraceptives. The manufacturers of Esmya® (ulipristal acetate 5 mg) advise avoiding concomitant use.
  • Antihypertensives — the hypotensive effect may be antagonized. 
    • Monitor blood pressure, and adjust the dose of antihypertensive medication accordingly.
  • Antidiabetic drugs — oestrogens and progestogens antagonize the hypoglycaemic effect. 
    • Monitor blood glucose.
  • Antifungals (such as fluconazole, itraconazole, ketoconazole, and voriconazole) — modest increase in plasma levels of oestrogens and/or progestogens. Possible increased risk of adverse effects.
    • Vaginally administered antifungals (such as miconazole) are unlikely to affect the contraceptive efficacy, however, antifungal ovules may increase the risk of ring breakage.
  • Erythromycin — modest to marked increase in plasma levels of oestrogens and/or progestogens. Possible increased risk of adverse effects.
  • Etoricoxib — oestrogen levels increased by around 40% with etoricoxib, doses of 60 mg or more. Increased risk of adverse effects.
  • Statins — minor to modest increase in plasma levels of oestrogens and/or progestogens. Not likely to be clinically significant. 
  • Diuretics — oestrogens may antagonize the diuretic effect.
  • Thyroid hormones — oestrogens may increase the requirements for thyroid hormones. 
    • Monitor thyroid function, and adjust the dose of levothyroxine accordingly.
  • Theophylline — oestrogens reduce the excretion of theophylline. 
    • The theophylline dose may need to be reduced.
  • Selegiline — oestrogens and progestogens may increase plasma levels of selegiline, leading to an increased risk of toxicity. Avoid concomitant use.
  • Tacrolimus — oestrogens, norethisterone enantate, and gestodene possibly increase tacrolimus levels. 
    • Monitor serum tacrolimus levels. 
  • Retinoids — the adverse effect on lipid levels may be additive with isotretinoin. 
    • Monitor lipid levels. 
  • Triptans — combined hormonal contraceptives appear to modestly raise the levels of frovatriptan, naratriptan, and zolmitriptan and slightly increase levels of sumatriptan.
    • Combined hormonal contraceptives should not be used in woman who have migraine with aura. 
• Be aware that vaginally administered spermicides have no effect on the efficacy or safety of the CVR.

Lamotrigine

• If the woman is taking lamotrigine monotherapy, advise her to change to an alternative method of contraception, as concurrent use with the combined vaginal ring (CVR) may reduce seizure control. If the woman still wishes to use the CVR:
  • Seek specialist advice, as the maintenance dose of lamotrigine may need to be increased as much as two-fold according to clinical response, and serum lamotrigine levels should be monitored.
  • A continuous regimen should be used to avoid lamotrigine toxicity during the hormone-free interval.
  • Advise the woman to seek medical advice before stopping the CVR.
    • The maintenance dose of lamotrigine may need to be decreased by as much as 50% if the CVR is stopped, according to clinical response and lamotrigine adverse effects,
• If the woman is taking lamotrigine plus sodium valproate, the CVR may not affect seizure control.
• If the woman is taking lamotrigine plus an antiseizure medication that induces liver enzymes (such as carbamazepine), follow the advice in the section on Liver enzyme-inducing drugs.

Griseofulvin

If a woman is taking griseofulvin, advise that:

• There is a possibility of reduced efficacy of the combined vaginal ring (CVR).
• Griseofulvin has been associated with birth defects in animal models. Very limited human data are more reassuring, but teratogenicity cannot be ruled out until further information is available. 
• Condoms should therefore be used reliably in addition to the CVR while taking griseofulvin and for 28 days after treatment cessation.

Basis for recommendation

These recommendations are based on the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guidelines Combined hormonal contraception [CoSRH, 2023a] and Drug interactions with hormonal contraception [CoSRH, 2022], as well as the relevant manufacturer's Summary of Product Characteristics [EMC, 2022d].

Griseofulvin

• Griseofulvin teratogenicity has been observed in animal models at doses higher than the human equivalent.  Data on griseofulvin use in human pregnancy do not prove teratogenic effects, but are too limited to rule these out [Reprotox, 2024; TERIS, 2024]. 
• There are case reports of contraceptive failure and menstrual irregularities in women taking oral contraceptives who were using griseofulvin [Reprotox, 2024].
• As a precaution, the FSRH therefore recommends reliable use of condoms in addition to a combined hormonal contraceptive during treatment with griseofulvin [CoSRH, 2022] and the manufacturer of griseofulvin recommends that additional contraceptive measures are continued for a month following treatment cessation [EMC, 2024b].

Basis for recommendation

These recommendations are based on the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guideline UK Medical Eligibility Criteria for contraceptive use [CoSRH, 2016].

How long can the combined contraceptive vaginal ring be left in place?

• Stop the combined contraceptive vaginal ring at 50 years of age, and switch to one of the following contraceptive methods:
  • A non-hormonal method such as the copper intrauterine device (Cu-IUD). For more information, see the CKS topic on Contraception - IUS/IUD. 
  • The progestogen-only pill, progestogen-only implant, or levonorgestrel intrauterine system. For more information, see the CKS topics on Contraception - progestogen-only methods and Contraception - IUS/IUD.

Basis for recommendation

These recommendations are based on the Faculty of Sexual and Reproductive Healthcare (FSRH) clinical guidelines Combined hormonal contraception [CoSRH, 2023a], Contraception for women aged over 40 years [CoSRH, 2023c], the UK Medical Eligibility Criteria for contraceptive use [CoSRH, 2016], and expert opinion in a medical textbook, Contraception today [Guillebaud, 2016].