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.


This guidance deals with claims made within testimonials. For the rules on using testimonials in marketing communications, and evidencing they are genuine, please see “Testimonials and Endorsements”.

Testimonials must relate to the product advertised and claims in a testimonial that are likely to be interpreted as factual must not mislead or be likely to mislead the consumer (Rules 3.46 and 3.47). The Code applies to claims made in testimonials in the same way that they apply to claims elsewhere in advertising. Unless they are clearly subjective, marketers must hold evidence for all claims made in testimonials. When making health, or medicinal claims, additional rules will apply.

Hold evidence for objective claims

Any objective claims made in testimonials, such as those about the efficacy of a product, must be supported by sufficient objective evidence to support the claim.

A testimonial which stated “My mum is diabetic […] Frank's is the only ice cream she can have, in fact it's the only dessert at all she can have” was considered problematic. The ASA understood that people with diabetes were able to consume all types of food, including ice-cream, within the context of a healthy and balanced diet, and that specialist foods were not necessary. Because the claim implied that the ice cream was suitable for diabetics because it had special characteristics, and that no similar foods were suitable for diabetics when that was not the case, the ad was considered misleading (Frank’s Ice Cream Ltd, 29 March 2023).  The ASA also upheld complaints about a testimonial which described an individual’s theory regarding “hexagonal water” because it considered consumers would interpret the claims as being in relation to a theory based on evidence, which was not the case (Water for Health Ltd, 3 July 2013).

Although some testimonials often feature the views of the person who gave it, if those views can also be understood to be efficacy claims, then they should not be included in advertising, unless supported by sufficient evidence. A testimonial which stated "... these products really work and if you compare with the price of plastic surgery you'll see that they are not expensive at all ..." described the products as alternatives to surgery, and implied they were as effective as surgery. While the ASA acknowledged that the testimonial might have been a genuinely held opinion, it was also an objective claim. Because they were not provided with objective evidence to show that body sculpture was an effective alternative to surgery the testimonial was considered problematic (Rodial Ltd, 11 January 2012).

Health or medicinal claims

Section 15 of the CAP Code sets out the rules which specifically relate to marketing communications concerning food, food supplements and associated health or nutrition claims.  These rules apply to any claims made in in testimonials used in advertising. See Section 15 of the Code and ‘Food: health and nutrition general’ for full details.

Section 12 of the CAP Code sets out the rules that apply to marketing communications for Medicines, Medical Devices, Health Related products and Beauty Products. CAP has written a number of AdviceOnline articles on the topic of healthcare. See Section 12v and ‘Healthcare: overview’ for full details.

Ads for water filters which made multiple claims to treat acid reflux, including claims in testimonials which promoted the cessation of acid reflux medication, breached the Code because they were not supported by evidence, and because they discouraged essential treatment for health conditions for which medical supervision should be sought, a breach of rule 12.2 (Phox Water Ltd, 2 November 2022).

Testimonials are not evidence

Testimonials alone do not constitute substantiation so marketers should not rely on testimonials as support for any direct or implied claims made in the marketing communication. Customer survey responses which made positive comments about saving money on energy bills were not considered adequate substantiation for savings claims (Bright Networks Ltd t/a Bright Heating, 9 January 2013). In February 2015, an advertiser submitted testimonials in support of efficacy claims for a copper bracelet in the treatment of restless leg syndrome and the ASA ruled that personal or customer endorsement alone did not constitute adequate substantiation (Halcyon Bracelets, 18 February 2015).


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