The Advertising Standards Authority (ASA) has published new research into how patients interpret weight-loss treatment advertisements.
The findings show that, out of 2,030 participants, most believe weight-loss treatment advertisements can place pressure on individuals to lose weight and may target vulnerable audiences. The ASA explains that while many patients can define prescription-only medicines, they struggle to identify specific products, and fewer than half recognise GLP-1 treatments as prescription-only. The ASA says the research forms part of its ongoing efforts to identify and tackle advertising of prescription-only weight-loss medicines, which are prohibited from being promoted to the public under UK law and advertising rules.
The regulator shares its research, which exposed strong public support for restrictions on advertising weight-loss injections, was largely due to concerns about safety and misuse. The ASA notes patient reports about explicit language, body mass index eligibility criteria and extreme weight-loss claims signalling that an advertisement is promoting prescription-only treatments.
Alongside the research, the ASA shares its recently published enforcement report, highlighting improved compliance across the sector. The ASA states that, using its AI-based monitoring system, it analysed more than 95,000 online advertisements between February 2025 and January 2026, and identified around 900 potentially non-compliant ads. The ASA outlines targeted action towards the advertisers, carried out in collaboration with the Medicines and Healthcare products Regulatory Agency (MHRA) and the General Pharmaceutical Council (GPhC), helped raise compliance levels to 99% by January 2026.
Jessica Tye, regulatory projects manager at the ASA, commented, “Our investigations and rulings, AI-assisted monitoring and enforcement work has led to a significant improvement in the number of pharmacies and clinics now sticking to the rules. That’s welcome, but our latest research shows just how much weight-loss is in the public consciousness and how they interpret and respond to ads. We’re committed to continuing to monitor the sector, work with the MHRA and GPhC, and to take action where problem ads appear.”
Julian Beach, executive director of healthcare, quality and access at the MHRA, said, “This research is a valuable contribution to our understanding of how weight-loss treatment advertising is perceived by the public. These medicines have important safety considerations and must only be used under appropriate clinical supervision. The 99% compliance rate is an encouraging sign that our action and close collaborative working with the ASA is making a real difference in protecting people from advertising that is unlawful or misleading.”