The Advertising Standards Authority has banned the first social media posts promoting prescription-only weight-loss injections through discount codes and referral links. The UK advertising regulator ruled that posts on Instagram, TikTok and Facebook advertising medicines including Mounjaro constituted illegal advertising of prescription-only drugs.
The banned posts directly named prescription medicines, used related hashtags, showed injection pens, or encouraged weight-loss "journeys" alongside offering discounts. The ASA held both brands and individuals responsible for following advertising rules, targeting posts linked to online pharmacies Voy, Zava, MedExpress and prescribing service UK Meds Direct.
Catherine Drewett, investigations manager at the ASA, said: «Today's rulings send a clear message that affiliate marketing is not a loophole and that promoting prescription medicines through social media, whether as a brand, influencer or customer, is against the law and our rules. We'll continue take swift action in this area to make sure the rules are followed and that people are protected from harmful and irresponsible ads.»
The ASA warned that promoting prescription-only weight-loss drugs irresponsibly and illegally puts people at serious risk. The regulator emphasized this is a priority area, noting that members of the public might promote these medicines without realizing their posts are advertisements subject to strict rules.
Company responses
A spokeswoman for Voy said: «The posts referenced in the ruling were made independently by customers of our service back in 2024 as part of a referral scheme for our weight-loss programme. These posts were first brought to our attention in June 2025, and since we have strengthened our controls around referral activity and influencer engagement. Clinical decisions — including whether medication is suitable — are always made privately between patients and qualified clinicians, and no influencers or referrers play any role in diagnosis, prescribing or medical advice.»
Zava expressed disappointment with the ruling. The online pharmacy said: «We are committed to being a responsible and compliant healthcare organisation that follows regulation and guidance from the ASA. While we were disappointed by the ruling, we note that we had no commercial or affiliate relationship with the social media users who created the posts in question, and as a business we do not have oversight or control over content shared independently by members of the public on their own social media channels.»
Regulatory action
Julian Beach, interim executive director of healthcare quality and access at the Medicines and Healthcare products Regulatory Agency, welcomed the rulings. He said: «Prescription-only weight-loss medicines carry real risks and must only be prescribed following a proper clinical assessment. The promotion of these medicines through affiliate schemes and social media circumvents important safeguards that exist to protect patients. We will continue to work closely with the ASA and General Pharmaceutical Council (GPhC) to take action against those who break the rules and put people's health at risk.»
Dionne Spence, chief enforcement officer at the GPhC, said: «These rulings from the ASA send a clear message that online providers are responsible for making sure that advertising rules are followed, including when working with individuals through affiliate or referral schemes. We welcome the action taken by the ASA and we have taken action to follow up with the pharmacies registered with us.»
Affiliate or referral schemes typically reward individuals for sharing links or discount codes when others use them. Under UK law, prescription-only medicines cannot be advertised to the public. The ASA's ruling clarifies that companies controlling affiliate schemes are responsible for ensuring posts comply with advertising regulations.
Note: This article was created with Artificial Intelligence (AI).
