What this report covers
This report examines the impact of enforcement against paid online ads for prescription-only medicines used for weight management between February 2025 and January 2026. It highlights significant improvements in compliance following targeted enforcement action.
Key findings
- We captured and analysed over 95,000 unique paid online ads from 44 advertisers across Google, Meta, TikTok and display advertising. Around 35,000 of these related to weight management services.
- Around 900 ads from 38 advertisers were assessed as likely to break the rules by promoting prescription-only medicines for weight loss.
- The main issues included naming prescription-only medicines, wording that implied them and images of branded injection pens.
- Following targeted monitoring and enforcement, compliance improved significantly over the period, reaching 99% compliance with the Enforcement Notice by January 2026.
- When monitoring began in February 2025, 7% of ads were likely to breach the rules. This fell to 4% after the first Enforcement Notice in April and to 1% after the second notice in September.
Compliance action taken
CAP contacted 46 advertisers, including some referred following complaints to the ASA as well as those identified through monitoring, and instructed them to amend or remove non-compliant ads. In all but one case, advertisers provided assurances that the ads would be changed or withdrawn. One advertiser that did not respond was referred to the General Pharmaceutical Council for consideration under its rules, and that investigation is ongoing.
We will continue to monitor the sector and intervene where advertising changes or new risks emerge.
CAP Enforcement Reports
CAP Enforcement Reports explain the action CAP takes to address non-compliance in specific sectors. They also show how these actions affect overall compliance rates.
These reports use insights from our AI-based Active Ad Monitoring system to track ads in certain sectors.