Research
What a customer review is allowed to imply
A testimonial about how well something worked is read as a claim that it works. Federal advertising guides put the burden of proving that claim on the seller, not on the customer who wrote it.
A review is treated as the seller talking
The Federal Trade Commission publishes guides on endorsements and testimonials in advertising. They are the rules that decide what a customer quote on a product page is understood to be saying.
The core move is simple. Once a seller puts a consumer testimonial about performance into an advertisement, the guides read the advertisement as claiming the product works for the purpose shown. The seller then has to be able to back that claim.
The guides require substantiation "to support express and implied claims made through endorsements." The standard is the seller's own. It is the same manner the seller "would be required to do if it had made the representation directly, i.e., without using endorsements."
The word "implied" is doing real work there. A quote never has to say "this cured me" for the advertisement to be read as making a health claim.
The sentence that answers the whole question
One line in the consumer-endorsement section settles a great deal about peptide marketing. The guides state that "Consumer endorsements themselves are not competent and reliable scientific evidence."
So a wall of five-star testimonials is not evidence for the claim it carries. It is the claim. The evidence has to sit somewhere else.
That is the same distinction this site draws when it separates what a seller says from what has been published about a compound. A grade reflects what studies show, and a testimonial section changes nothing about it.
It also explains a pattern worth watching for. A product page with a great deal of review volume and no cited study is not offering a weaker form of proof. It is offering a different thing entirely.
One person's result reads as everyone's result
The guides address what a single strong outcome communicates. An endorsement about "a central or key attribute of the product" will likely be read as saying that experience is representative.
The full phrase is worth having, because it anticipates the obvious objection. It says such an endorsement represents "what consumers will generally achieve with the advertised product in actual, albeit variable, conditions of use."
If a seller cannot substantiate that, the guides do not say the testimonial must go. They say the advertisement "should clearly and conspicuously disclose the generally expected performance in the depicted circumstances," and the seller must be able to back that second figure too.
And a disclaimer only counts if it works. The guides add that "To be effective, such disclosure must alter the net impression of the advertisement so that it is not misleading."
Bona fide users, and pictures of them
Three conditions attach to the person behind the quote, and each is checkable in a small way from the outside.
The endorsement has to be genuine. The guides open by saying endorsements "must reflect the honest opinions, findings, beliefs, or experience of the endorser."
The person has to have actually used the product. Where an advertisement represents that the endorser uses it, "the endorser must have been a bona fide user of it at the time the endorsement was given." The seller may keep running the endorsement only while it has good reason to believe that is still true.
And the quote cannot be reshaped in the telling. A seller need not use the exact words, but the endorsement "may not be presented out of context or reworded so as to distort in any way the endorser's opinion or experience with the product."
The photograph is part of the claim
Images get their own rule, and it is the one most often missed on a supplement or peptide page.
The guides state that using an endorsement "with the image or likeness of a person other than the actual endorser is deceptive if it misrepresents a material attribute of the endorser."
The published example is specific. A site pairs accurate acne testimonials with purchased stock photos of people with near-perfect skin, and the guides say those images "misrepresent the improvements to the endorsers' complexions."
A second example in the same passage runs a truthful weight-loss testimonial beside a photograph of someone far smaller than the endorser actually is. The text says the image "misrepresents the product's effectiveness," even though the words were true.
What a seller may do to its own review section
The guides reach past individual testimonials and into the machinery of a review section. This is the provision that covers filtering, sorting and quiet deletion.
It names the actions first. A seller is on the hook when "procuring, suppressing, boosting, organizing, publishing, upvoting, downvoting, reporting, or editing consumer reviews of their products."
Then it names the limit. Sellers "should not take actions that have the effect of distorting or otherwise misrepresenting what consumers think of their products, regardless of whether the reviews are considered endorsements under the Guides."
Read the last clause. The provision applies even where the reviews would not count as endorsements at all, which closes the gap a seller might otherwise argue its way into.
Who else is on the hook
Liability does not stop at the company whose name is on the vial. The guides name the intermediaries directly.
They say that "Advertising agencies, public relations firms, review brokers, reputation management companies, and other similar intermediaries" may be liable for their part in creating or spreading endorsements they know or should know are deceptive.
Endorsers carry their own exposure. A person who is not an expert may be liable where their claims about performance go beyond their own experience, or were never made or approved by the seller.
A published example goes further than most readers expect. It treats a seller who buys fake negative reviews of a competitor as engaged in a deceptive practice, even though a paid attack on a rival is not an endorsement under the guides.
What these guides are, and what they are not
The guides are not a statute. They state plainly that they "represent administrative interpretations of laws enforced by the Federal Trade Commission," and that they address how section 5 of the FTC Act applies to endorsements.
They then say what non-compliance risks. Practices inconsistent with them "may result in corrective action by the Commission under section 5" where the Commission has reason to believe the conduct falls within what the statute makes unlawful.
So the practical answer sits in between. Nothing in the guides makes a testimonial illegal by itself, and nothing in them lets a seller point at a customer and step back from the claim.
The part carries its own effective marker. Its source line records publication at 88 FR 48102 on July 26, 2023, which is the version now in force.
How to use this while shopping
Four questions turn the guides into something you can apply in about a minute on any seller's page.
Does the page pair a strong individual result with any statement of what people generally get? Where a headline outcome stands alone, the guides say a typicality claim is being made whether or not the seller intended one.
Do the faces match the words? Stock photography beside a specific physical result is exactly the pattern the published examples describe.
Can you see any review that is not positive, and can you sort or filter to find one? A review section with no visible range is consistent with a curated one.
And separately, is there a disclosure of any relationship between the seller and the person speaking? That is a different section of the same guides, and it is covered on this site in the article on advisory boards.
Key takeaways
- A consumer testimonial about performance is read as the seller claiming the product works.
- The guides state that consumer endorsements are not competent and reliable scientific evidence.
- A single strong result is read as representative unless the page discloses what people generally get.
- A disclaimer only counts if it changes the net impression the advertisement leaves.
- The endorser must have been a genuine user, and the quote may not be reworded to distort it.
- Sorting, filtering or deleting reviews is covered, even where the reviews are not endorsements.
- The guides are administrative interpretations, enforced through section 5 of the FTC Act.
Frequently asked questions
Are customer reviews evidence that a peptide works?
Not under these guides. The consumer-endorsement section states that consumer endorsements themselves are not competent and reliable scientific evidence. A testimonial is treated as a claim the seller is making, not as support for it. The substantiation has to come from somewhere else, which is why a page heavy on reviews and light on cited studies is not offering weaker proof so much as a different category of thing.
Does a "results may vary" line fix an unusual testimonial?
Only if it changes what the advertisement communicates. Where a seller cannot substantiate that an endorser's experience is representative, the guides say the advertisement should clearly and conspicuously disclose the generally expected performance. The seller must be able to back that second figure as well. The guides then add that to be effective the disclosure must alter the net impression of the advertisement so that it is not misleading. A small line under a dramatic claim usually does not.
Can a seller delete negative reviews from its own site?
The guides cover this directly and broadly. They list procuring, suppressing, boosting, organizing, publishing, upvoting, downvoting, reporting and editing consumer reviews. A seller should not take actions that have the effect of distorting or misrepresenting what consumers think of its products. The provision applies whether or not the reviews would count as endorsements, so a seller cannot escape it by arguing the reviews were unsolicited.
Does the photograph next to a testimonial matter?
Yes, and it is a separate rule. The guides say using an endorsement with the image or likeness of someone other than the actual endorser is deceptive where it misrepresents a material attribute of the endorser. The published examples pair truthful text with stock photographs and conclude that the images misrepresent the result. Accurate words beside a misleading picture are still a misleading advertisement.
Do the FTC guides have the force of law?
They are administrative interpretations rather than a statute. The part says so about itself: the guides address the application of section 5 of the FTC Act to endorsements and testimonials, and provide a basis for voluntary compliance. Practices inconsistent with them may result in corrective action by the Commission under section 5. So the guides are the map, and section 5 is the road the enforcement actually runs on.
Is a review site itself covered by these rules?
Intermediaries are named. The guides say advertising agencies, public relations firms, review brokers, reputation management companies and other similar intermediaries may be liable for their roles in creating or disseminating deceptive endorsements. They may also be liable for disseminating endorsements without a necessary disclosure of a material connection. That reaches a great deal more of the internet than the company whose product is being sold.
Sources
Each document below is named as it names itself, with the date printed on that document rather than the day it was read.
- Title 16 Code of Federal Regulations section 255.1, General considerations — read in full, including the honest-opinion requirement at (a), the no-distortion rule at (b), the bona fide user condition at (c), intermediary liability at (f), the image and likeness rule at (g), and the stock-photograph examples at (h)(6) — Electronic Code of Federal Regulations, Office of the Federal Register, July 2023
- Title 16 Code of Federal Regulations section 255.2, Consumer endorsements — substantiation and the statement that consumer endorsements are not competent and reliable scientific evidence at (a), the typicality rule and net-impression test at (b), actual consumers at (c), and the review-manipulation provision at (d) — Electronic Code of Federal Regulations, Office of the Federal Register, July 2023
- Title 16 Code of Federal Regulations section 255.0, Purpose and definitions — the guides as administrative interpretations of laws enforced by the Commission, the application of section 5 of the FTC Act, and the example treating purchased negative reviews of a competitor as deceptive — Electronic Code of Federal Regulations, Office of the Federal Register, July 2023