Weight loss injections such as Wegovy, Mounjaro and Saxenda have seen a significant rise in popularity in the UK in recent years as an effective new treatment for weight loss.
Advertising of these medicines in the UK is heavily regulated. Providers of weight loss injections must therefore ensure that their marketing activity complies with applicable UK medicines legislation and healthcare codes.
Prescription-only medicines cannot be advertised to the public
In the UK, weight loss injections are classified as prescription-only medicines (POMs). Under the Human Medicines Regulations 2012, businesses must not:
- Advertise POMs directly to the public
- Name a POM in promotional material aimed at the public
- Promote a specific branded weight loss injection on social media, websites, Google Ads, or email marketing
This includes:
- Website landing pages
- Paid search adverts
- Influencer marketing
- Before-and-after transformation campaigns
- Promotional emails
- Sponsored social posts
Even factual content can be considered promotional if it encourages patients to request a specific POM.
What you can do: Promote the service, not the medicine
Businesses are permitted to advertise:
- A weight management service
- A medical weight loss clinic
- A doctor-led obesity treatment programme
- A consultation for clinically supervised weight management
However, businesses must not:
- Name the prescription medicine
- Imply guaranteed access to a specific drug
- Trivialise obesity treatment
- Suggest cosmetic-only use
By way of example:
Likely to be compliant advertising:
- Struggling with weight management?
- Our clinician-led weight management service offers personalised consultations to assess which treatments may be appropriate for you.
- Book a confidential consultation today to discuss your options.
Likely to be non-compliant advertising:
- Lose up to 15% of your body weight with Skinny Jab – now in stock!
- No GP needed. Quick online approval and fast delivery to your door.
- Start your transformation today #SkinnyJab
Importantly, regulators will look at the substance rather than the form of the offering i.e. if something is marketed as a "weight loss service" but in reality is simply: (i) an online questionnaire; (ii) a remote prescriber review; and (iii) supply of a POM, with no structured nutritional or lifestyle component, there is a risk that regulators could view that as misleading.
The Advertising Standards Authority (ASA) and the Competition and Markets Authority would look at the overall consumer impression. If “service” implies wraparound support, coaching, or multidisciplinary care, but that isn’t actually provided, that’s where exposure arises.
Avoid indirect promotion
Regulators such as the Medicines and Healthcare products Regulatory Agency (MHRA) and the ASA assess advertising based on overall impression, not just the wording used in the promotion. This means that businesses should avoid:
- Using brand names in URLs (e.g., /buy-SkinnyJab-online)
- Creating pages clearly designed to drive demand for a named POM
- Suggesting a medicine is “in stock now”
- Using phrases such as “ask our prescriber for Skinny Jab”
Even educational blogs and customer testimonials must be carefully structured. If the primary purpose appears to generate demand for a named prescription product, it may be considered unlawful advertising by both the MHRA and ASA.
Claims must be accurate and balanced
Any claims about weight loss outcomes must:
- Be evidence-based
- Not exaggerate results
- Avoid guarantees
- Include appropriate medical context
- Avoid misleading before-and-after imagery
Businesses must not:
- Suggest rapid or dramatic weight loss without context
- Use phrases like “miracle jab” or “skinny injection”
- Downplay risks or side effects
- Claim treatment is suitable for everyone
Remember: obesity is a recognised medical condition. Advertising must reflect this and not present treatment as a cosmetic or lifestyle enhancement. Marketing should focus on clinical suitability, health outcomes, and medical oversight.
Recent ASA rulings have highlighted that ethical considerations, particularly body image exploitation, are firmly at the centre of ASA enforcement decisions. In a number of new rulings published after Christmas, the ASA upheld complaints where adverts were found to be:
- promoting weight-loss injections directly to the public and “irresponsibly” exploiting body image concerns in paid-for social media ads;
- targeting post-baby weight loss and associated insecurities, including ignoring safety warnings for breastfeeding, while promoting POMs; and
- implying medicinal effects beyond approved use, such as suggesting a medicine could help people resist food temptation.
These rulings signal that adverts that suggest medicinal benefits or depict weight-loss medicines (even without naming specific POMs) can still breach the rules around the promotion of POMs if they lead consumers to misunderstand the nature of the product.
Social media & influencer risks
Businesses should take particular caution with:
- Influencer testimonials
- Patient transformation posts
- Paid partnerships
- Social media promotions
Even if a patient shares their experience, if the content is incentivised or promoted by a clinic or business that sells weight loss drugs, it becomes advertising and must comply with relevant POM restrictions. Using a brand name in a hashtag (e.g., #SkinnyJab) in promotional content can therefore constitute unlawful advertising.
Other weight loss treatments and unauthorised medical claims
In addition to weight loss injections, dermal patches have been advertised as an aid for weight loss, treating illness and providing general health benefits. Many of these dermal patches advertised as containing GLP-1 do not contain the actual, approved, prescription only GLP-1 agonist medications, which are only available through regulated pharmaceutical channels.
If a business intends to use medical claims in the advertising of dermal patches, it may only make such medical claims where authorised by the MHRA. Businesses are not permitted to make medicinal claims for products not authorised by the MHRA. Complaints relating to adverts claiming that dermal patches cause weight loss have been upheld by the ASA, where the products were not licensed by the MHRA.
If making objective claims about products, you should have evidence to substantiate them, pursuant to rule 3.7 of the UK Code of Non-broadcast Advertising and Direct & Promotional Marketing (CAP Code). Businesses are also reminded that unauthorised medicinal or health claims cannot be made through testimonials or reviews, and brands should monitor and remove customer statements that breach the rules.
Finally, adverts must be created with a clear sense of social responsibility, as required under Rule 1.3 of the CAP Code. For example, an advert promoting a slimming dermal patch was found to be irresponsible because it appeared to endorse the pursuit of extreme thinness, depicting an unhealthily thin woman as the “after” result of using the product.
Key takeaways for businesses
- Medical weight management offers significant growth opportunities, but strict regulatory boundaries apply.
- Regulators are closely scrutinising advertising, so avoid promoting POMs directly to the public.
- Position services as clinically led, focus on consultation and medical oversight, and ensure all claims are evidence-based and able to be substantiated.
- Responsible, compliant marketing builds trust and protects your business from enforcement action and reputational risk.
- Regularly review your marketing materials across all promotional platforms to ensure ongoing compliance and support sustainable growth.
In short: advertise responsibly, evidence everything, and keep POMs out of your public-facing marketing.
We would be pleased to discuss how we can support you in keeping your advertising compliant and reviewing your current claims strategy.
