Weight Loss Medication in the UK: Licensed Options, NHS Access and Getting a Prescription

Several medicines are licensed in the UK to help with weight management, alongside a reduced-calorie diet and more physical activity. They differ in how they are taken, who they are licensed for and how you can get them. This guide lists each one, explains the NHS routes set by NICE and how a private prescription works, using the UK product information, NICE and the MHRA.

Licensed Weight Loss Medicines at a Glance

Wegovy, Mounjaro, liraglutide (Saxenda), Foundayo, Mysimba and orlistat.

These medicines are licensed in the UK for weight management:

• Wegovy (semaglutide): weekly injection, or a daily tablet.

• Mounjaro (tirzepatide): weekly injection.

• Liraglutide, for example Saxenda: daily injection. Whether a liraglutide brand is licensed for weight management depends on the brand, so check its product information.

• Foundayo (orforglipron): daily tablet.

• Mysimba (naltrexone/bupropion): tablets twice a day.

• Orlistat: capsules with meals, as Xenical 120 mg on prescription or alli 60 mg from a pharmacy.

All except alli need a prescription. Ozempic and Rybelsus contain semaglutide but are licensed for type 2 diabetes, not weight management.

Weekly and Daily Injections

Wegovy and Mounjaro weekly, liraglutide daily; all reduce appetite.

Wegovy and Mounjaro are once-weekly injections given with a pen; liraglutide (for example Saxenda) is a once-daily injection. Wegovy and liraglutide act on GLP-1 receptors; Mounjaro acts on both GIP and GLP-1 receptors. All three reduce appetite. The dose starts low and goes up in steps to reduce stomach side effects.

See what is Wegovy, how Mounjaro works and how to inject Wegovy.

Tablets and Capsules

Wegovy tablets and Foundayo daily, Mysimba twice a day, orlistat with each main meal.

• Wegovy tablets and Foundayo are once-daily GLP-1 tablets.

• Mysimba combines naltrexone and bupropion and acts on the brain's hunger and reward areas. NICE does not recommend it on the NHS. See Mysimba.

• Orlistat blocks some of the fat you eat from being absorbed, rather than reducing appetite. It is taken with each main meal. See orlistat.

There are no licensed weight loss medicines in the form of patches, drops or oral liquids; see GLP-1 patches, drops and oral solutions.

Who Are They Licensed For?

Mostly adults with a BMI of 30+, or 27+ with a weight-related condition; orlistat from 28 with risk factors.

Most are licensed for adults with a body mass index (BMI) of 30 kg/m² or more, or 27 kg/m² or more with at least one weight-related condition such as high blood pressure, abnormal blood fats, sleep apnoea or type 2 diabetes. Orlistat is licensed from a BMI of 28 kg/m² with risk factors. Wegovy and Saxenda are also licensed for some adolescents aged 12 and over.

A prescriber checks your health, other medicines and any reason a medicine would not suit you, such as pregnancy, before prescribing.

Getting Weight Loss Medication on the NHS

Through routes set by NICE: tirzepatide phased in, semaglutide and liraglutide in specialist services.

NICE guideline NG246 sets where each is prescribed on the NHS in England:

• Tirzepatide (Mounjaro): in primary care or a specialist weight management service. Under NICE TA1026, it is for adults with a BMI of at least 35 and at least one weight-related condition. NICE's TA1026 page summarises NHS England's interim commissioning guidance, which introduces it in phases: first for people with a BMI of 40 or more and four of five listed conditions, from around June 2026 for a BMI of 35 to 39.9 with four, and from around March 2027 for a BMI of 40 or more with three.

• Semaglutide (Wegovy): in a specialist weight management service, for up to 2 years, under NICE TA875, for adults with at least one weight-related condition and a BMI of at least 35, or 30 to 34.9 if they meet the criteria for specialist referral.

• Liraglutide: in a specialist service in secondary care, under NICE TA664, for adults with a BMI of at least 35, non-diabetic hyperglycaemia and a high risk of cardiovascular disease.

• Orlistat: can be prescribed in any setting, and is available at a lower dose from a pharmacy.

NICE uses BMI thresholds usually 2.5 lower for people from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean backgrounds. Access also depends on NHS England's commissioning and local services. Prescriptions are free in Scotland, Wales and Northern Ireland; in England the standard prescription charge applies unless you are exempt.

Getting Weight Loss Medication Privately

A prescriber assesses you and a registered pharmacy supplies it; avoid unregulated sellers.

Privately, a prescriber assesses whether a medicine is suitable, usually through an online or in-person consultation, and a registered pharmacy supplies it. The MHRA's advice:

• Only take GLP-1 medicines that have been prescribed to you by a healthcare professional.

• If you are offered a GLP-1 medicine without the need for a prescription, walk away.

• Check the pharmacy is registered with the General Pharmaceutical Council (GPhC) in Great Britain, or the Pharmaceutical Society of Northern Ireland (PSNI).

Weight-loss products sold illegally online "may be fake, contaminated, incorrectly dosed, or contain powerful ingredients not listed on the packaging", the MHRA warns.

When Treatment Is Reviewed

If less than 5% is lost: 6 months for tirzepatide and semaglutide, 12 weeks for liraglutide and orlistat, 16 for Mysimba.

Each medicine has a point at which treatment should be reviewed if weight loss is limited:

• Tirzepatide and semaglutide: if less than 5% of starting weight has been lost after 6 months (for tirzepatide, on the highest tolerated dose).

• Liraglutide: stop after 12 weeks on the 3 mg dose if less than 5% has been lost.

• Orlistat: stop after 12 weeks if less than 5% has been lost.

• Mysimba: stop after 16 weeks if less than 5% has been lost.

For what the trials found, see Mounjaro weight loss and Wegovy weight loss.

Side Effects and Pregnancy

Mostly stomach-related; GLP-1 medicines are not for use in pregnancy.

The GLP-1 medicines most often cause stomach side effects such as nausea, diarrhoea, vomiting and constipation, mostly while the dose is increasing. Orlistat mainly causes oily stools and urgency, especially after fatty meals. Seek immediate medical attention for persistent, severe stomach pain on a GLP-1 medicine.

None of the GLP-1 medicines should be used in pregnancy, and the MHRA advises against taking them while breastfeeding. Orlistat must not be used while breastfeeding. NICE notes that tirzepatide users on the contraceptive pill should switch to a non-oral method or add a barrier method for 4 weeks after starting and after each dose increase, and that severe diarrhoea on orlistat can stop the pill working. Report suspected side effects to the MHRA Yellow Card scheme.

Frequently Asked Questions