Background
This Ruling forms part of a wider piece of work on prescription-only medicines (POMs) used for weight loss, identified for investigation following complaints received. See also related rulings published on 9 July 2025, 17 December 2025 and 11 February 2026.
Summary of Council decision:
Three issues were investigated, all of which were Upheld. Mumsnet Ltd were investigated in relation to Issue 1 only.
Ad description
An advertorial for Zava, seen on Mumsnet’s website on 3 September 2025, was accessed from an image in the website’s carousel of a woman and two children in a street. A heading stated, “Medicated weight loss, an expert guide” and underneath was smaller text stating, “Created by ZAVA”. After clicking on the image, the advertorial was also headed “Medicated weight loss, an expert guide”, followed by the sub-heading “Everything you need to know about medically supervised weight management” and the text “CREATED BY ZAVA”.
Other text stated, “What is medical weight management and how does it work? Clinical lead Dr Clair Grainger […] explains ‘Medical weight management includes clinically assessed, prescription-only medications […] These treatments are prescribed after a full medical review […] a medically supervised route rather than over-the-counter or cosmetic alternatives’ […]”. That text was followed by a box headed “Save £10 on your first weight loss consultation”. The box included a clickable button labelled “Find out more” that directed to a webpage on Zava’s website.
Further text stated, “How do prescription-based treatments support weight loss? […] Dr Clair notes, […] ‘To support weight-related health conditions, some people may be prescribed treatment following a clinical assessment’ […] What to look for in a provider […] Like all prescription medicines, weight loss treatments may cause side effects […] Maintenance is the continued use of GLP1s […] Our doctors carefully review your progress and can continue prescribing if this remains suitable for you. Are medicated weight loss treatments available on the NHS? ‘Yes, the NHS offers treatments for patients meeting specific BMI thresholds and weight-related conditions, often requiring discussion with a GP’ Dr Clair explains”.
The ad featured another box which included the text “About ZAVA”, “ZAVA is a registered online healthcare provider […]” and a further clickable button labelled “Learn more about ZAVA’s consultation services”.
Further text stated, “About the expert Dr Clair Grainger […] has worked in hospitals throughout Edinburgh and London […] is a Clinical Lead doctor and has worked at ZAVA since 2018 […] About the author […] Rebecca Roberts is a Senior Content Editor here at Mumsnet […] she commissions, writes and edits content designed to help parents navigate real life […] is also on her own weight loss journey as part of a medically supervised plan […]”.
Issue
The ASA challenged whether the ad:
1. was obviously identifiable as a marketing communication and did not make clear its commercial intent; and
2. used a health professional to endorse a medicine.
The complainant challenged whether:
3. the ad breached the Code because it promoted prescription-only medicines (POMs) to the public.
Response
1., 2. & 3. Health Bridge Ltd t/a Zava submitted their contract with Mumsnet. They said it demonstrated that the article was not initially intended as an ad and showed that a doctor was responding to specific clinical queries.
They said they had provided editorial content and images, and that the promotional discount on the associated imagery was created separately to the clinical content. They said the placement of the imagery and promotional banners was not intended to be alongside clinical information, and that Mumsnet were responsible for page layout, design and hosting.
Zava said that the discount was for their entire weight-loss service, and not to promote or discount specific medications. That service included consultation, administration costs, pharmacy dispensing costs, applicable treatment costs, weight-loss resource packs, and ongoing access to doctors’ support and their messaging platform.
Zava believed the information in the article was factually correct and non-biased, and that the clinical content provided a holistic view of weight management rather than promoting a specific medication. They said the article made it clear that weight management should be overseen by a registered healthcare professional, and included healthy behaviour such as diet and activity aside from treatment.
They said that the editorial content from the doctor was not intended as an ad for POMs. The article did not name a specific POM or a POM active ingredient; and it did not highlight the use of a POM or the benefits of one POM over another.
Zava said they had conducted a review of how the article was constructed and had decided to remove it, pending further review of the content to ensure compliance with the CAP Code. They also said that, for any further work with organisations such as Mumsnet, they would ensure that they were clear on their intention to comply with the CAP Code.
In relation to 1., Mumsnet, who also submitted a copy of the contract, said they retained editorial control over the presentation of the article, with Zava providing factual information. They said that to ensure ads were obviously identifiable as marketing communications, the article and carousel tile were labelled “Created by Zava” and featured Zava’s logo. That was consistent with their standard format for commercial partner content, which was intended to make the sponsored nature of pieces apparent and to distinguish them from editorial features. They submitted examples.
Mumsnet believed the label, “Created by Zava”, directly alongside the headline and byline signalled to users that the article was created as part of a commercial partnership rather than an independent editorial. They said that Zava was repeatedly referenced as the provider of the medical services described in the article, which further reinforced the commercial context and avoided the impression that the content was editorially neutral.
Mumsnet said expectations around native advertising labels evolved and, as they updated their site, they were: enhancing the visibility and placement of sponsored labels; reviewing the use of space above the banner image for disclosures; and considering more explicit terminology such as “Advertisement Feature”.
Assessment
1. Upheld
The CAP Code stated that marketing communications must be obviously identifiable as such and must make clear their commercial intent, if that was not apparent from the context. It also stated that marketers and publishers must make clear that advertorials are marketing communications, for example by heading them “advertisement feature”.
The ASA first assessed whether the article was a marketing communication that fell within the remit of the CAP Code.
We understood that Zava had a commercial agreement with Mumsnet, under which Mumsnet had been paid to publish a brand-led article on its website. The contract between Zava and Mumsnet required the content to be published within and for a particular period of time. We acknowledged Zava’s comments that they had provided factual clinical information to be used in the article, and that Mumsnet believed they had editorial control over the presentation of that information. However, the article referred throughout to the type of weight-loss service and weight-loss medication supplied by Zava and included text such as “Our doctors carefully review your progress”. It also featured clickable buttons, including one labelled “Learn more about ZAVA’s consultation services” that directed from Mumsnet to Zava’s website where Zava’s services could be purchased. We considered those references went beyond factual clinical information and promoted Zava’s services. We therefore considered that the inclusion of text promoting and linking to Zava’s services as well as the contractual requirement to publish the content within a particular window of time indicated that Zava had editorial control over the content. Because of that, we considered the article was an advertorial and fell within the remit of the Code.
We then assessed whether the advertorial was obviously identifiable as a marketing communication.
The feature was in the style of an editorial article. For example, the heading included the text “an expert guide”, a sub-heading stated, “Everything you need to know about medically supervised weight management” and the author, a Mumsnet Senior Content Editor, was described as “she commissions, writes and edits content designed to help parents navigate real life”.
Although it contained text stating “CREATED BY ZAVA” together with Zava’s logo, that text was small in comparison to the heading and appeared further down the page under an image of a mother and her child. In any case, we did not consider this made sufficiently clear that the piece was a marketing communication. Furthermore, the article did not contain any label or identifier, such as “advertisement feature”, to make clear upfront, either in the thumbnail in the website’s carousel that linked to the article or in the article itself, that it was a marketing communication.
We therefore concluded that it was not obviously recognisable as a marketing communication and breached the Code.
On that point, the ad breached CAP Code (Edition 12) rules 2.1, 2.3 and 2.4 (Recognition of marketing communications).
2. & 3. Upheld
The CAP Code stated that the prescription-only medicines (POMs) or prescription-only medical treatments must not be advertised to the public.
We acknowledged that the ad did not name a specific POM active ingredient or POM and that the clickable links that led to Zava’s website did not lead to specific treatments. However, we considered that some of the text focused specifically on the use of weight-loss POMs; for example, “‘Medical weight management includes clinically assessed, prescription-only medications […] These treatments are prescribed after a full medical review […] a medically supervised route rather than over-the-counter […] alternatives’”; “How do prescription-based treatments support weight loss?”; “Like all prescription medicines, weight loss treatments may cause side effects”; and “Our doctors carefully review your progress and can continue prescribing if this remains suitable for you”. We considered that those references to “prescription-only medications”, “a medically supervised route rather than over-the-counter”, “prescription-based treatments” and “prescription medicines” promoted POMs to the public.
The ad also referred to the use of “GLP1s”. We understood that GLP-1 (Glucagon-like peptide-1) medication was a class of POMs used for weight loss. We therefore considered the reference to “GLP1s” in the ad promoted POMs to the public.
We sought advice from the Medicines & Healthcare products Regulatory Agency (MHRA). They expressed concern that some terms, such as “GLP1s” and “prescription medicines”, could be likely to lead a member of public to request a POM.
For those reasons, we considered that the ad promoted POMs to the public.
The CAP Code also stated that marketers must not use health professionals to endorse medicines. The advertorial quoted Dr Clair Grainger and described her as “a Clinical Lead doctor” with Zava, who had “worked in hospitals throughout Edinburgh and London”.
While neither the overall advertorial nor the quotes from Dr Grainger referred to a specific POM active ingredient or POM, it included statements from her such as “‘Medical weight management includes clinically assessed, prescription-only medications […] These treatments are prescribed after a full medical review […] a medically supervised route rather than over-the-counter […] alternatives".
We therefore considered that the references to, and quotes from, Dr Grainger in the ad constituted an endorsement of medicines by a health professional.
We acknowledged that Zava had removed the ad. However, because at the time the ad appeared, we considered it promoted POMs to the public and used a health professional to endorse medicines, we therefore concluded that it breached the Code.
On those points, the ad breached CAP Code (Edition 12) rules 12.12 and 12.18 (Medicines, medical devices, health-related products and beauty products).
Action
The ad must not appear again in the form complained of. We told Health Bridge Ltd t/a Zava and Mumsnet Ltd to ensure that all future marketing communications were obviously identifiable as such. We also told Health Bridge Ltd t/a Zava not to promote POMs to the public nor use health professionals to endorse medicines in future.
