ASA partners with MHRA and GPhC to reinforce rules on the advertising of weight-loss drugs online

Our Compliance team have today published a joint Enforcement Notice with the Medicines and Healthcare products Regulatory Agency (MHRA) and General Pharmaceutical Council (GPhC), making clear that ads for named weight-loss POMs are prohibited, including online, on social media and by influencers, and any remaining ads must be removed immediately.

We are also issuing a wider update on our work in this area, which has been informed by our world leading AI-based Active Ad Monitoring system (AAMS), enabling us to monitor weight-loss POM ads at pace and scale.

In December 2024, we issued a warning to businesses and individuals who, against the law and our advertising rules, were targeting members of the public with ads for weight-loss prescription-only medicines (POMs).

Since then, we have continued to take strong action to tackle weight-loss POM ads targeted at people in the UK.

No-one operating in this industry can say they have not been warned that weight-loss POMs must not be promoted to the public.

ASA Investigations

We have launched 12 investigations which are underway into whether ads are promoting weight-loss POMs. All of those investigations focus on online ads, which is where we have observed the vast majority of issues. Those investigations concern common approaches seen in weight-loss POM ads and will provide further clarity for advertisers and businesses over what is acceptable in ads. They include investigations into paid-for online ads and affiliate and influencer marketing.

Formal rulings will be published once those investigations are complete. Following that, the Enforcement Notice will be updated to reflect our findings. Further monitoring and enforcement action will follow.

We continue to keep a close watch on approaches used by advertisers in this sector and we do not rule out launching further investigations.

Active Ad Monitoring system insights

In January, we undertook a wide sweep of online ads for weight-loss providers using data science. That fast review of available data included an in-depth look at adverts on some online platforms, along with a more qualitative view of ads in other media.

We found around 1,800 unique paid-for weight-loss ads from December and January which we identified as potentially advertising a POM. Around a quarter of those ads featured a named medication; some of which included a POM, which is in clear breach of our rules. There were also many examples of content that are currently under investigation by us. Those findings have informed our approach to tackling this issue.

CAP enforcement

The Committee of Advertising Practice (CAP)’s Compliance team have continued to take enforcement action against ads which feature named weight-loss POMs, which are in clear breach of the rules. CAP contacted 20 advertisers in December 2024 and January 2025 who were featuring named weight-loss POMs in ads found by the above AAMS review.

A follow-up in early March, which involved reviewing around 600 ads identified as potentially advertising a POM, found that a quarter of those 20 advertisers were still using named weight-loss POMs in their ads, but that most other ads featuring named weight-loss POMs had not been published for some time.

Whilst this is only one snapshot of data, combined with a reduction in complaints on this topic to the ASA, it provides an early indication that ads featuring named weight-loss POMs have likely reduced in volume and that some advertisers have taken notice of warnings from regulators, including us.

Whilst we welcome this positive sign of improvement, which relates to ad featuring named POMs only, no ads for weight-loss POMs should be appearing online or elsewhere.

Through our continued work in this area, we will be targeting a continued significant improvement in reducing the volume of paid ads that break the rules and using all possible means to effectively address any high volume and address any ongoing issues with advertisers who appear unwilling or unable to follow the rules. Where advertising is not brought into compliance despite repeat warnings, CAP will not hesitate to take further enforcement action where necessary, including referrals to regulatory partners.

ASA Regulatory Projects Manager, Jess Tye said:

“We have made clear from the outset of this initiative that advertising weight-loss prescription-only medicines to the public is against the law and the advertising rules. Our Enforcement Notice, sent to relevant businesses such as GPhC registrants who include pharmacies and pharmacists, strengthens our approach and supports our ongoing work. Alongside this, we’ve launched multiple proactive ASA investigations, carried out monitoring and enforcement work using our AI-based Active Ad Monitoring system and are working closely with our partners at MHRA and GPhC with the aim of significantly reducing the number of problem ads that are appearing.”

Julian Beach, MHRA Interim Executive Director, Healthcare Quality and Access, said the MHRA took concerns about the illegal promotion of prescription-only weight-loss medicines to the public very seriously.

“The promotion of prescription-only medicines is not only against the law but also puts people’s health at risk.

“We scrutinise complaints we receive about the alleged advertising of prescription-only medicines to the public. By working in close partnership with other regulators, we can together take strong, coordinated action to stop those responsible for the promotion of these prescription only medicines and ensure advertising rules are followed.”

Chief Enforcement Officer at the GPhC, Dionne Spence, said:

“Our role is to ensure that appropriate safeguards are in place to protect and assure the public.

“It is vital that people receive prescription-only medicines, such as those used for weight management, only after having an appropriate consultation, and when their prescriber has independently verified that the medicines are clinically appropriate for them.

“Adverts and special price offers should not be used for prescription-only medicines as they are likely to promote the specific POM.

“GPhC inspectors will continue to inspect pharmacies to ensure our standards are being met and will be looking for evidence that our Guidance for registered pharmacies providing pharmacy services at a distance, including on the internet is being followed.

“We will be working closing with our regulatory partners to ensure that prompt and proportionate action is taken where necessary to protect the public.”


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