Sometimes, yes. Prescription weight-loss medicines work by reducing appetite or changing how your body digests food. They are usually recommended alongside diet and exercise changes, not instead of them. If you're thinking about weight loss, start by talking to your doctor or nurse.
Who might benefit from weight-loss medicines?
Doctors use body mass index (BMI) to help decide. Medicine may be considered if lifestyle changes haven't worked and your BMI is 30 or greater, or 27–29.9 with a weight-related condition such as diabetes, heart disease or high blood pressure. Extra belly fat alongside certain health conditions can also make medicine appropriate.
GLP-1 medicines
GLP-1 medicines were first developed for diabetes but also help many people without diabetes lose weight. Examples include tirzepatide (Zepbound, Mounjaro), semaglutide (Wegovy, Ozempic), liraglutide (Saxenda) and orforglipron (Foundayo). Most are weekly or daily injections under the skin; semaglutide is also available as a tablet, and orforglipron only comes as a pill. They increase insulin release after meals, slow digestion and help you feel full sooner.
Other weight-loss medicines
For people who can't take GLP-1 medicines, doctors sometimes prescribe pills such as phentermine-topiramate (Qsymia), naltrexone-bupropion (Contrave), orlistat (Alli, Xenical) or phentermine (Adipex-P, Lomaira). Each works differently and has its own side-effect profile.
Side effects
All weight-loss medicines can cause side effects. GLP-1s commonly cause nausea, vomiting, diarrhoea and constipation, especially when starting or increasing the dose. Other medicines have their own side effects — always read the information provided with your prescription and discuss any concerns with your doctor.
Managing cost
Weight-loss medicines can be expensive. Some manufacturers offer direct-purchase programmes or savings schemes. Be very cautious about 'compounded' versions sold online — they don't meet the same safety and quality standards as approved medicines. Ask your doctor or pharmacist about safe, affordable options.
What else you should know
For most weight-loss medicines to keep working, you need to keep taking them — stopping usually leads to weight regain. Long-term use can affect nutrient intake and muscle mass, so a good diet and regular activity remain essential. If you take a medication for another condition that causes weight gain, your doctor may be able to switch it. Avoid unproven herbs and supplements that claim to help with weight loss. If you take a GLP-1 medicine and have surgery planned, tell your surgical team — the medicine may need to be paused before anaesthesia.
Key takeaways
- Weight-loss medicines work alongside diet and exercise — not instead of them.
- GLP-1s (tirzepatide, semaglutide, liraglutide, orforglipron) are the most commonly prescribed options today.
- Side effects, cost and the need for long-term use are important considerations.
- Always discuss weight-loss medicines with your doctor before starting — and before surgery.