Introduction

Using medication as part of a weight management plan (medicated weight loss) has often been frowned upon in the past, viewed by some as “cheating” or “taking the easy route”. Greater knowledge about the multifactorial reasons for obesity is gradually altering these views.

GLP-1 medicines have been used on and off licence for weight loss for several years and there is definitive evidence of their efficacy. The science of GLP-1s continues to emerge and improved health outcomes have been demonstrated beyond their role in diabetes and weight loss. There are some rare serious adverse effects that pharmacists need to be aware of.

Orlistat, meanwhile, works by reducing the fat absorbed by the body from food and has been used for over 25 years as an oral formulation with a well-known efficacy and safety profile.

Evidence and experience show that for any weight loss medication, lost weight will be regained without a dual approach of medication plus long-term changes to diet and physical activity. This toolkit is a concise guide to the key clinical features of medications for weight loss, their benefits and adverse effects, and a brief summary of the main issues to bear in mind.

It briefly considers orlistat, then focuses mainly on the GLP-1s e.g. semaglutide (Wegovy) and tirzepatide (Mounjaro), sometimes called the ‘incretins’.