Encyclopedia entry

ASA rules on weight-loss advertising

The Advertising Standards Authority (ASA) enforces the Committee of Advertising Practice (CAP) code on UK advertising. Prescription-only medicines (POMs) cannot be advertised to the public under CAP rule 12.12. Tirzepatide (Mounjaro), semaglutide (Wegovy) and liraglutide (Saxenda) are all POMs. The ASA and MHRA have increasingly enforced these rules against consumer-facing GLP-1 advertising, with rulings and warnings against clinics and pharmacies that named these medications in search and social ads.

What is not allowed

• · Naming a POM weight-loss medication in consumer advertising.
• · Before-and-after imagery linked to a named POM medication.
• · Pricing the medication directly in social or search advertising.
• · Promotional codes or discount offers for POM weight-loss medications.
• · Influencer endorsements of named POM medications.

What is allowed

• · Generic advertising of a weight-management clinic or service ("medical weight loss programme") without naming the medication.
• · Editorial commentary on the medications themselves (this site is editorial).
• · Pharmacy advertising of services, with conservative wording.
• · Healthcare professional-facing communications (not consumer-facing).

Why enforcement tightened

The ASA confirmed that many UK clinic and pharmacy ads naming Mounjaro and Wegovy in search and social were in breach. Several major clinics paused consumer ads while compliance reviews ran. By Q1 2026 most UK clinics had restructured advertising around generic "GLP-1" or "medical weight loss" framing, with the named medication only appearing post-consultation on the prescriber side.

Related: MHRA medicines classification · how we are funded.