Can you advertise weight-loss medicines in the UK?

What does the law actually say?

It says you may not publish an advertisement that is likely to lead to the use of a prescription-only medicine. That is regulation 284 of the Human Medicines Regulations 2012, in Part 14, which covers advertising. The only exceptions are ministerially approved vaccination campaigns and campaigns about the spread of pathogens. Weight-loss medicines have neither. Mounjaro (tirzepatide), Wegovy (semaglutide) and Saxenda (liraglutide) are all prescription-only, and so is the oral form of semaglutide licensed for weight management.

Three features of Part 14 matter for a pharmacy. First, "advertisement" is defined widely. Regulation 7 covers anything designed to promote the prescription, supply, sale or use of a medicine, in any medium. The Blue Guide summarises it as "any thing or any activity which is intended to encourage prescription or supply by healthcare professionals and use of medicines by the general public". Reference material, factual informative statements, trade catalogues and price lists are excluded, but only if they make no product claim. So is correspondence answering a specific unsolicited question.

Second, regulation 280 sets general principles for any advert that is permitted. It must be consistent with the summary of product characteristics, encourage rational use by presenting the product objectively, and not mislead. Third, regulation 303 makes breach a criminal offence. On summary conviction the penalty is a fine up to the statutory maximum. On indictment it is a fine, imprisonment for up to two years, or both. Part 14 also treats causing another person to publish an advert as publishing it yourself, which is why paying an agency or an influencer does not move the liability.

The test is "likely to lead to the use of" a POM. It does not require a brand name. That single phrase is what makes the indirect references discussed below unlawful, and it is why the MHRA and the ASA read the whole customer journey, not just the headline.

Can you advertise the service instead?

Yes, and this is the whole basis of lawful weight-loss marketing. Appendix 6 of the MHRA's Blue Guide deals with medicinal treatment services, including online clinics and pharmacies. Its position is that such services "may promote the service they provide" but "should not draw attention to specific prescription only medicines". The MHRA repeats the same line on every 2026 enforcement page: "Treatment-service providers may promote the service or consultation offered."

Appendix 6 then gets specific about websites. Any mention of a prescription-only medicine on the home page "is likely to be considered as advertising". The home page may give indicative prices for treating a particular medical condition, but not for a named medicine. Other pages may carry a factual list of prices for available treatments and pack sizes, provided it makes no product claims. Descriptions should say "XXX is used to treat", never "XXX, the best, fastest or strongest treatment for". Icons or other features encouraging the purchase of POMs should not be used. And it should be clear that the customer "is being offered a medical consultation and that this may or may not lead to the provision of a prescription".

Appendix 6 also expects a service to give a balanced overview of the range of therapeutic options for the condition. A weight-loss page that only ever leads to one injectable is not balanced, whatever the wording. The MHRA's Voy decision, published on 9 January 2026, shows how the journey is judged. A sponsored social media advert for orlistat, an over-the-counter medicine, said "Start from £94 a month for the same medication" and carried the company's chief medical officer's image and signature. Its links led to pages promoting two prescription-only weight-loss medicines. The MHRA found the price claim misleading, the professional endorsement improper and the links a promotion of POMs to the public. The company withdrew the advert.

What counts as an indirect reference?

Anything the public will read as the injection. The Advertising Standards Authority, the MHRA and the GPhC issued a joint enforcement notice on 11 April 2025, after named-medicine adverts spread across Facebook, Instagram, TikTok, sponsored search and influencer content. It was sent to all 13,214 registered pharmacies. On 23 September 2025 the three bodies updated it, because advertisers had swapped brand names for descriptions. The updated notice names the substitutes.

The ASA's own explanation of its July 2025 rulings lists the exact phrases it acted on: "Weight Loss Injections", "Weight Loss Pen", "Obesity Treatment Jab" and "GLP-1". It acted on unbranded pens, branded pens and vials too. If your creative contains any of them, it is inside the ruled-against set, not a grey area.

What have the ASA and MHRA actually ruled?

Enough to remove any doubt about how the rule is applied. On 9 July 2025 the ASA published nine rulings against advertisers of prescription-only weight-loss medicines, six of them GPhC-registered pharmacies. The rulings came from a monitoring sweep rather than complaints. Between February and June 2025 the ASA's AI-based system captured more than 20,000 adverts from 35 high-priority pharmacies, about 10,000 of them for weight-loss treatments. More than 99 per cent complied with the named-medicine prohibition; 80 referenced a named drug directly. The rulings went beyond names, treating "GLP-1" and pen imagery as breaches in their own right. The GPhC said it would review the six rulings for further enforcement action, and confirmed it refers pharmacies to the ASA and MHRA when inspections find advertising concerns.

The MHRA's enforcement runs monthly. Its September 2025 statement said it had taken action against more than 25 businesses in 2025 for promoting prescription-only weight-loss medicines to the public. Its published investigations for 2026 name the companies below. Every entry records the same failing: direct or indirect promotion of weight-loss POMs, including references to GLP-1s or weight-loss injections. Every entry records the same outcome: the company amended its advertising after MHRA action on complaints.

That is 18 companies in six months, and the list includes a national multiple, a price comparison site and a clinic named twice. The Tesco entry, published on 7 July 2026, drew a GPhC response reported the next day: "We will not hesitate to act where those that we register fail to meet our standards". Nobody on the list was prosecuted. All of them were named, which for a business trading on trust is the sanction that costs.

Who enforces, and what can they do?

Three regulators, and since April 2025 they pool what they find. The MHRA's Advertising Standards Unit enforces Part 14. GOV.UK's guidance on advertising medicines says it usually pursues informal resolution first: amending or withdrawing the advert, publishing a correction, or requiring future material to be vetted before use. It publishes the outcome with the company's name. Prosecution under regulation 303 remains available, and the guidance is explicit that breaches are criminal offences carrying fines and up to two years' imprisonment.

The ASA enforces the CAP Code, whose rule 12.12 states that no prescription-only medicine may be advertised to the public. It can rule against an advertiser, require the advert to be withdrawn, and refer persistent offenders to its compliance team or to the MHRA. Its monitoring is proactive: the enforcement notice says AI-based active ad monitoring is scanning for breaches, so an advert can be caught with nobody complaining.

The GPhC's lever is the register. Its notice of 11 April 2025 says it may take enforcement action against the pharmacy, the owner and the superintendent pharmacist. It may also investigate the fitness to practise of every pharmacy professional involved. Advertising is now a documented inspection theme. The GPhC's April 2026 review of weight-management services found that 17 per cent of the 1,307 concerns it received between January 2024 and December 2025 were about advertising. That is how the GPhC's weight-loss enforcement now works, as our article on GPhC policing of online weight-loss supply sets out in full.

What about influencers, affiliates and social posts?

The same law applies, and the pharmacy is on the hook. Regulation 284 binds any person who publishes an advertisement, and the April 2025 enforcement notice states that it covers paid adverts, organic social media content, sponsored search results and influencer marketing. An influencer posting about their Mounjaro results with your discount code is publishing an advert for a POM. You caused it to be published. The GPhC's April 2026 review recorded reports of pharmacies paying influencers, particularly on TikTok, to promote weight-management medicines using discount codes. Those reports sit inside the 17 per cent of concerns about advertising.

Two further traps arrived in 2026. On 18 June 2026 the ASA, MHRA and GPhC issued a joint statement after seeing businesses promote pipeline products. The examples included waiting lists for newer oral and injectable weight-loss products, and newly licensed oral GLP-1s. An unlicensed medicine cannot be advertised at all, under regulation 279. A waiting list for one is a promotion of it. And the oral semaglutide that went on sale on 6 July 2026 is a POM like the injections. The MHRA's Julian Beach put the principle plainly: "A consultation with a healthcare professional is the most appropriate way to determine suitable treatment options for an individual patient".

Patient testimonials raise their own questions under the CAP Code and consumer law, which we cover in our article on patient reviews. The short version for weight loss: a review that names the medicine is an advert for the medicine, and hosting it on your site makes you the publisher.

What can you still say?

Quite a lot, provided the subject is the service and the reader is offered a consultation rather than a product. The following wording is consistent with Appendix 6 and the enforcement notice.

Getting the advert right does not get the service right. What must happen after the click, from independent BMI verification to follow-up, is covered in our guide to the verification duties.

Key takeaways

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