UK weight loss medicine rules, in plain English

Who can get Mounjaro, Wegovy and the new tablets, what the NHS offers, what an online pharmacy must check and what the safety regulator says. Every point is linked to the official source.

Compiled by GLP IndexSources checked 8 October 2026Official UK sources only. Not medical advice

In the UK every GLP-1 weight loss medicine is prescription only. A private prescriber can prescribe within the medicine's licence, usually a BMI of 30 or more, or 27 or more with a weight related condition. The NHS uses tighter rules set by NICE and NHS England. Online pharmacies must verify your weight, height or BMI independently before a supply.

Start with a question

GLP-1 medicines in the UK: which are licensed for weight lossThe brands, what each one is licensed for and where each stands with the NHS.
Who can get weight loss medicine in the UKThe BMI rules for a private prescription, for NICE and for the NHS, side by side.
Weight loss injections on the NHS: who qualifies and whenThe phased NHS rollout of Mounjaro and how Wegovy is offered.
Buying weight loss medicine online: the UK rulesWhat a registered online pharmacy must check before a supply, and how to spot a fake.
MHRA safety advice for weight loss medicinesSide effects, pancreatitis, contraception, pregnancy, surgery and how to report a problem.
Why weight loss medicines are not advertised in the UKThe law on prescription only medicine adverts and the regulators' enforcement notice.
Who regulates weight loss medicines in the UKMHRA, NICE, the NHS, GPhC and the ASA: who does what, in plain English.
UK weight loss medicine timeline: every key decisionLicences, NICE guidance, NHS rollout dates and safety updates in date order.
NHS vs private: what weight loss medicine costs in the UKWhat you pay on the NHS against live private prices from GLP Index.

The short version

Prescription only. A healthcare professional must assess you first. Do not buy from beauty salons or social media. Source: MHRA.
Private rules follow the licence. Foundayo, for example, is authorised for adults with a BMI of 30 or above, or 27 to under 30 with at least one weight related condition. Source: MHRA.
NHS rules are tighter. NICE recommends Mounjaro for a BMI of at least 35 with at least one weight related condition, and NHS England is phasing access in over several years. Sources: NICE, NHS England.
Online pharmacies must verify. A questionnaire alone is not enough. The prescriber must check your weight, height or BMI through an independent route. Source: GPhC.
No adverts. Prescription only medicines may not be advertised to the public. Source: ASA, MHRA and GPhC.
Report problems. Report a side effect or a suspected fake through the Yellow Card scheme.

Tools

This section explains published UK rules in plain English. GLP Index gives no medical advice. A UK prescriber decides whether a treatment suits you.

Questions

Are weight loss injections legal in the UK?

Yes, with a prescription. Every GLP-1 medicine is a prescription only medicine. A healthcare professional must assess you before a prescription is issued.

Can I get weight loss medicine on the NHS?

Some people can. Wegovy is offered through specialist NHS weight management services. Mounjaro is rolling out in phases, starting with people in the highest clinical need.

Can I buy weight loss medicine privately?

Yes, from a registered pharmacy after a consultation with a prescriber. The pharmacy must check your weight, height or BMI through an independent route.

Who checks these rules are followed?

The MHRA regulates the medicines. The GPhC regulates pharmacies in Great Britain. The ASA regulates adverts. NICE decides what the NHS in England should offer.

Official sources

Every rule on this page comes from the sources below. GLP Index checked each one on 8 October 2026.

Medicines and Healthcare products Regulatory Agency. GLP-1 medicines for weight loss and diabetes: what you need to know. First published 5 June 2025, updated 5 February 2026.
National Institute for Health and Care Excellence. Tirzepatide for managing overweight and obesity (TA1026). Published December 2024.
National Institute for Health and Care Excellence. Semaglutide for managing overweight and obesity (TA875). Published March 2023.
NHS England. Weight management injections. Checked 8 October 2026.
NHS England. Interim commissioning guidance: NICE TA1026 tirzepatide. Reviewed April 2026.
General Pharmaceutical Council. Providing weight management services: FAQs. Checked 8 October 2026.
General Pharmaceutical Council. Guidance for registered pharmacies providing pharmacy services at a distance, including on the internet. February 2025.
Advertising Standards Authority, MHRA and GPhC. Enforcement notice: advertising of prescription-only medicines used for weight management. 23 September 2025.
Medicines and Healthcare products Regulatory Agency. UK first in Europe to authorise orforglipron for weight management and type 2 diabetes. 10 August 2026.
Medicines and Healthcare products Regulatory Agency. Yellow Card scheme: report a side effect or a fake medicine. Live service.