Note: This advice is given by the CAP Executive about non-broadcast advertising. It does not constitute legal advice. It does not bind CAP, CAP advisory panels or the Advertising Standards Authority.

The Code applies to: 

• Ads on the internet including on social media and on companies’ own websites 

• Press ads 

• Commercial e-mail and text messages 

• Posters/billboards 

• Leaflets and brochures 

• Direct mail 

• Ads on the internet including on social media and on companies’ own websites, specifically: 

• paid-for ads on social media, such as image or video ads on Facebook, Instagram 

and TikTok 

• non-paid-for, or organic, content on a pharmacy’s and other provider’s own social 

media channels 

• sponsored searches on search engines such as Google 

• influencer marketing (see Remit: Social media) 

• affiliate ads   

Prescription-only medicines

Don’t advertise POMS to the public

Promote the “consultation” itself, rather than the product

Don’t claim customers can achieve a specific rate or amount of weight loss

Don’t refer to an excessively fast rate of weight loss in individuals.

Don’t feature health professional or celebrities

Don’t use irresponsible claims or imagery

Don’t use before and after photographs

GLP-1 POM comparisons

Prescription only medicines

Over-the Counter and general medicines should not be advertised to the public unless the marketer holds a valid licence, marketing authorisation or registration and the claims in the ad should conform to the authorisation (Rule 12.11). Marketers should refer to the Medicines and Healthcare products Regulatory Agency (MHRA) for advice. 

Prescription-only medicines (POMs) are a specific class of medicine. A POM must be prescribed by a doctor or other authorised health professional and it must be dispensed from a pharmacy or from another specifically licensed place. Rule 12.12 states: 

Prescription-only medicines or prescription-only medical treatments may not be advertised to the public. 

Following many complaints about ads for POM treatments for weight-loss in 2020, CAP issued an enforcement notice against marketers advertising these medicines to the public.  This was updated in April 2025.  

Don’t advertise POMs to the public

Prescription-only medicines (POMs) cannot be advertised to the public (rule 12.12). (The Angel Clinic, 11 January 2023).

There is a small exemption to the inner pages of a clinic or pharmacy’s own website (but not the homepage or a proactively linked landing page) which is explained in more detail in CAP Advice on Prescription only medicines (websites).   

In traditional non-broadcast media, such as leaflets, press ads, brochures, posters and even on sponsored ads, the ASA considers almost every reference (whether the medicine is named or not) to a POM to be a promotion of a POM and therefore a clear breach of rule 12.12. The rule also applies to posts on advertiser’s own social media pages and other online ads (Juniper Technologies UK Ltd, 15 February 2023). 

Any claims, images or references that consumers could understand to refer to prescription only medicines are likely to breach the Code. 

The ASA has considered the following claims and references and ruled that consumers will understand them to be advertising POMs: 

  • Reference to a class of  POMs (GLP-1) (Juniper Technologies UK Ltd, 9 July 2025), product names that reference the POM for example, semaglutide in SemaPen (SemaPen Ltd, 9 July 2025) or the name of the POM 

  • “Weight loss medications” alongside the claims “it is prescribed on the NHS” “Yes, there's […] reports and stuff. And I'm not telling anyone to go on this medication, but it is prescribed on the NHS”.  The ASA considered that readers would understand this to refer to press reports that people had suffered adverse reactions from taking injectable weight-loss medications and would therefore, in the context of this ad,  understand ‘weight loss medications’ to refer to POMs. (Yazen Health AB, 9 July 2025) 

  • “Obesity Treatment Jab”. The ASA ruled that consumers were likely to understand that to mean a weight-loss treatment that was administered by injection. Because all injectable forms of weight-loss medication are POMs the claim “Obesity Treatment Jab” promoted a POM to the public (Express Healthcare Ltd, 9 July 2025) 

  • “weight loss pen” Because all injectable forms of weight-loss medication were POMs the reference to “Weight Loss Pen” in the ad promoted a POM to the public. (SemaPen Ltd, 9 July 2025) 

  • “weight loss injections” Because all injectable forms of weight-loss medication were POMs the reference to “Weight Loss Injections” in the ad promoted a POM to the public (Phlo Technologies Ltd, 9 July 2025 Juniper Technologies UK Ltd, 9 July 2025)   

  • “Weight loss treatments” if the ad is directly linked to a landing page that implies that the outcome of a consultation will be a POM or refers to a named POM  Phlo Technologies Ltd, 9 July 2025 PharmaRx Ltd, 9 July 2025). 

  • the image of an injection pen (branded or unbranded), The ASA ruled that, in the context of an ad for weight-loss treatment, because all injectable forms of weight-loss medication were POMs the image of an injection pen would be understood by consumers to mean a POM (Juniper Technologies UK Ltd, 9 July 2025).  

  • partial image of a medical injection pen (Hexpress Healthcare Ltd, 9 July 2025). 

  • the image of a vial of liquid. The image of a vial of liquid on the packaging shown in the ad, although unbranded, was likely to be understood by consumers to mean, in the context of an ad for weight-loss treatment, an injectable form of weight-loss medication.  The image of a vial of liquid therefore promoted POMs to the public. (Express Healthcare Ltd, 9 July 2025). 

  • Special offer, limited time or discounted prices that apply only to POMs (even if the price is not linked to the POM in the ad) (Phlo Technologies Ltd, 9 July 2025)

  • Juniper Technologies UK Ltd, 9 July 2025). 

  • “Treatments start from £139.50 per pen” The ASA understood that all injectable forms of weight-loss medication were POMs and readers were likely to understand a reference to a pen to refer to injectable weight loss medication. (Hexpress Healthcare Ltd, 9 July 2025). 

  • “ONCE-A-WEEK […] weight loss treatment”.  The ASA ruled that consumers were aware that weight loss POMs are administered weekly (and other weight loss meds are not) (Hexpress Healthcare Ltd, 9 July 2025). 

  • a direct link to a webpage that refers to a POM or implies that the outcome of a consultation would be a POM.  The ASA ruled against an ad that did not contain a direct reference to a POM, but linked to a landing page which featured an image of a medical injection pen with the word Mounjaro on it and stated “2. Choose treatment. Select from our recommended UK-licensed weight loss pens”. The landing page did not feature any other weight-loss treatments and there was a clear implication that Mounjaro or another weight-loss injectable pen, which were all POMs, would be the outcome of the online consultation. (Chequp Health Ltd, 9 July 2025) 

An ad may offer “a consultation for weight loss”, but it should not indicate that the likely outcome will be the prescription of a POM, by its content or by offering a POM on a landing page. 

Promote the “consultation” itself, rather than the product

Ensure that ads for weight loss treatment promote the consultation, or a medicine that can lawfully be advertised to the public, not a POM. 

References to POMs and POM treatments are prohibited, but a reference to a “consultation” on the type of treatment being offered could be acceptable if that reference is representative of the licence for that POM.  For example, the claim “a consultation for weight loss” might be considered acceptable in ads, provided the POM itself is not referred to (directly or indirectly such as through images of an injection or the use of the colloquial name of the POM, see above).  However, referring to a consultation doesn’t mean an ad won't breach the Code. The ASA has ruled that, where a POM would be the likely outcome of an online consultation, an ad that referred to a consultation promoted POMs and breached the Code. The ad linked to a page that featured an image of a medical injection pen with the word Mounjaro on it and claimed “Mounjaro Weight Loss Injections” and “Lose up to 25% of your body weight […] Weekly injection that supresses appetite and reduces cravings (Chequp Health Ltd, 9 July 2025) 

Don’t claim customers can achieve a specific rate of weight loss

The inner pages of a clinic or pharmacy’s own website (but not the homepage) may be excepted from the above.  See CAP Advice on Prescription only medicines (websites) for more information.  Rate of weight loss claims are only acceptable in these inner pages of websites if in line with the remaining advice in this article.  

Rule 13.9 states that ads must not contain claims that people can lose precise amounts of weight within a stated period or, that weight or fat can be lost from specific parts of the body. 

The ASA ruled against an ad which included the claim “LOSE OVER A FULL STONE IN JUST 2-4 WEEKS” because it referred to an amount of weight within a specific period (Skinny Revolution Ltd, 7 October 2020). 

Don’t refer to an excessively fast rate of weight loss in individuals.

Rate of weight loss claims are only acceptable on some inner pages of websites if in line with the remaining advice in this article (see above).

Rule 13.10 allows for claims about a featured individual’s weight loss provided the time frame during which the weight was lost is stated and provided the example is representative of the weight loss achieved by using the product.  A rate of weight loss for individual examples will also need to be in line with good nutritional practice. For those who are normally overweight, a rate of weight loss greater than 2 lbs (just under 1 kg) a week is unlikely to be compatible with good medical and nutritional practice. For those who are obese, a rate of weight loss greater than 2 lbs a week in the early stages of dieting could be compatible with good medical and nutritional practice.

In 2020 the ASA ruled against ads on a marketer’s own social media site which featured references to the use of POMs to aid weight loss (a breach of rule 12.12). The ad featured references to the specific amount of weight loss achieved by Kerry Katona and referred to a rate of weight loss of 3.5 pounds a week, which was not considered to be compatible with good nutritional practice (Skinny Revolution Ltd, 7 October 2020).

Don’t feature health professionals or celebrities

While only suitably qualified health professionals should administer POMs, using health professionals or celebrities to endorse any medicine breaches rule 12.18 of the CAP Code.

In 2020 the ASA upheld complaints about social media ads for a prescription-only weight control product posted by ‘celebrity’ and social-media influencer Gemma Collins.   The social media posts made direct and indirect references to a prescription-only weight loss product which the ASA considered to be a prohibited endorsement of a medicine by a celebrity (Skinny Jab Ltd, 7 October 2020).

Don’t use irresponsible claims or imagery

Marketers should be mindful that criticism or negative images of weight gain could be seen to be socially irresponsible, especially for young women who are already body conscious because of pre-existing societal pressures (regardless of their actual weight or size, and including those who were of a healthy weight).

Additionally, marketers should also avoid suggesting that weight loss treatments could be used by individuals who are not normally over-weight.  Such content may be considered to be socially irresponsible and may also be considered problematic if the medicine in question is only licensed to treat individuals who are obese or overweight.

In 2020, the ASA considered ads for a POM which featured a “before” image of a slim Barbie doll and an “after” image of an overweight Barbie doll, together with the claims “Me in Quarantine” and “Don’t let lockdown knock you back”. The ASA ruled that the ad was irresponsible because it poked fun at women’s physicality and played on those anxieties and that this was exacerbated due to the “lockdown” references (from the COVID-19 pandemic) which affected access to normal diet and exercise routines (Skinny Revolution Ltd, 7 October 2020).

Also in 2020, the ASA considered social media ads for POM treatment for weight-loss which featured an already slim model alongside the claims including “I’m gonna be coming out of lockdown half the size!!” and “Forgot to eat again”. Alongside the irresponsible references to forgetting to eat, the ASA ruled that that the message that people who were not overweight would benefit from weight loss treatment was also considered irresponsible (Skinny Clinic, 7 October 2020).

Don’t use before and after photographs

The use of before and after photographs is likely to be interpreted by the ASA as an advertising claim, which is not permitted for POMs (Rule 12.12). Marketers of POMs should, therefore, avoid featuring any before and after images in their marketing communications. If the marketer also promotes non-POM treatments alongside their POM counterparts, the use of before and after images may be acceptable if they are clearly attributed to the non-POM product.  The before and after photographs for non-POM products are also subject to the rules on Weight control and slimming and social responsibility.

GLP-1 POM comparisons

The ASA has ruled against ads for food supplements that state or imply that the advertised product has the same effect as those associated with prescription-only medicines used for weight loss. The ads breached the code because, by comparing them to GLP-1 injections, the ads implied similar effects and efficacy and thus were medicinal by presentation.  Because medicinal by presentation and not authorised, they breached the code that prohibited claims that a food can prevent, treat or cure human disease. (Arrae Inc, Evolution Slimming Ltd, Myota GmbH, Ovira Australia, The Clean Supps LLC, 6 August 2025)

Don’t claim that a food supplement could prevent, treat or cure human disease, or make medicinal claims for a product that does not have the necessary authorisation. The following examples are likely to be considered medicinal in this context:

  • claims that the product has an effect on GLP-1 production or provides other effects associated with prescription-only medicines used for weight loss.  claims to reduce hunger or cravings (Evolution Slimming Ltd, 6 August 2025)
  • Claims that imply a product has the same weight-loss effects as GLP-1 POMs
  • In the context of an ad refers to GLP-1, and consequentially made a comparison with POMs used for weight loss, the ASA also considered the following claims to be medicinal claims: “Supports blood sugar balance”, “Improve metabolic health”, “Struggling with […] stubborn weight?”, “Balanced Blood Sugar – No more energy crashes […] and Gut Health Support – Optimizes microbiome for digestion” and “your body’s natural metabolic switch!”.

As usual, don’t:

  • make specific health claims unless they were authorised on the GB Register, or general health claims unless they are accompanied by an authorised health claims
  • use medical professionals to endorse food supplements (or medicines) or make health claims which referred to the recommendation of a health professional. (Ovira Australia, 6 August 2025)
  • refer to a rate of weight loss (Arrae Inc, 6 August 2025)
  • Make a specific health claim in a product’s name (Ovira Australia, 6 August 2025)

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