FTC rules on health claims and testimonials in supplement ads

The FTC's rule of thumb is simple: a health claim in an ad needs solid scientific support before the ad runs, and a testimonial does not count as that support. Under the FTC's guidance, claims about the health benefits or safety of supplements generally need "competent and reliable scientific evidence," which usually means well-run human trials with a control group. A happy customer story can illustrate a claim, but it cannot prove one.

This guide explains what the FTC says about health claims, testimonials, expert endorsers and paid promoters, and how to use those principles as a filter when you read a sales page. It is general information about published FTC guidance, not legal or medical advice.

Who regulates supplement advertising: the FTC or the FDA?

Both, with different jobs. The FDA's consumer Q&A says the FTC regulates advertising, including infomercials, for dietary supplements, while the FDA is generally responsible for safety, quality and labeling. The FTC's own guidance describes the split this way: the FDA has primary responsibility for claims in labeling, such as the package and materials at the point of sale, and the FTC has primary responsibility for claims in all forms of advertising.

The FTC guidance defines advertising broadly. It includes packaging, brochures, websites and other digital content, social media and influencer marketing, press interviews, and even promotion through health care practitioners or other intermediaries. So a video sales page, an email and an influencer post all fall under the same truth-in-advertising principles.

One difference matters for readers. The FTC says it does not pre-approve health claims in advertising, and its law makes no bright-line distinction between a "structure/function" claim and a disease claim the way FDA labeling law does. It applies the same steps to any health-related claim. Its guidance is business advice and does not have the force of law, but it shows how the agency reads ads.

What is "competent and reliable scientific evidence"?

It is the FTC's standard for backing up claims about the efficacy or safety of health-related products. The agency defines it as tests, analyses, research or studies that were conducted and evaluated in an objective manner by experts in the relevant field, and that are generally accepted in the profession to yield accurate and reliable results. The evidence must also be enough in quality and quantity, looking at the whole body of relevant research, to show the claim is true.

The guidance goes on to say that substantiation of health benefits generally needs to come from randomized, controlled human clinical testing. It lists several factors that set how much proof is needed, including the type of product, the type of claim, and the consequences of a false claim. Claims that are hard for consumers to judge on their own, for example a benefit that could be subject to a placebo effect or that involves a condition that naturally varies, are held to a more exacting standard.

It also says a marketer must have at least the level of support it claims to have. If an ad says "scientists now agree," the advertiser needs evidence that scientists reached that consensus. Our review method compares a page's cited studies with what the label actually lists.

Do testimonials count as proof?

No. The FTC guidance says advertisers should not use a testimonial to make a claim that would be deceptive or could not be substantiated if the advertiser made it directly. It also says it is not enough that a testimonial reflects the honest experience of the person giving it. The advertiser still needs scientific evidence for the underlying claim that the product works for buyers the way it did for the endorser.

The guidance gives an example of a smartphone app with customer stories that their insomnia went away. It says those testimonials do not constitute substantiation. Another example describes a blogger who is paid to write that a supplement fixes acid reflux, and it says the marketer is liable for the blogger's claim and that the paid post needs a clear and conspicuous disclosure.

The same page warns that testimonials reporting results more dramatic than users can generally expect are likely to be deceptive, and that a line like "results not typical" does not fix the problem. In one example, a weight-loss ad quotes a woman who lost 16 pounds in eight weeks, while a good trial shows an average of only four pounds over placebo. The guidance says the fine print does not adequately tell consumers their result is likely to be much smaller, and that a plain statement of the typical study result placed next to the quote would be more effective.

Our DentaBiome review records that the site's legal disclaimer says its spokesperson is a fictionalized character. We describe what the page says. Whether a page meets the FTC's rules is a decision for the agency, but a story voice that is invented is a good reason to look for actual studies instead.

What do the Endorsement Guides say about paid promoters and doctors?

The FTC's Endorsement Guides, revised in 2023, rest on a basic principle: endorsements must be honest and not misleading. An endorsement must reflect the honest opinion of the endorser and cannot be used to make a claim the marketer could not legally make. If there is a connection between the endorser and the marketer that a significant minority of consumers would not expect and that would affect how they weigh the endorsement, it should be disclosed clearly and conspicuously.

Experts are treated more strictly. The health products guidance says an advertiser using an expert should make sure the expert is properly qualified to be described that way and has conducted an examination or testing of the product generally recognized in the field as enough to support the endorsement. One example describes a "Doctor" in an infomercial who is not licensed to practice medicine, has not reviewed the science on the ingredient, and holds a paid position at the company. The guidance says the ad is likely to be deceptive.

Affiliate links come up too. The FTC's Q&A says someone who earns a commission from purchases made through links should disclose that clearly and conspicuously, near the recommendation, and that "affiliate link" by itself may not be understood by consumers. We follow that principle, and we earn commissions on some links on this site. Our affiliate disclosure explains how, and why the scores do not depend on the payout.

Do disclaimers and "FDA" wording rescue a claim?

Not according to the FTC. Its guidance says the DSHEA label disclaimer ("this statement has not been evaluated by the FDA...") is not required in other forms of advertising, and that including it will not rescue an otherwise deceptive ad. In its example, an herbal supplement ad claims the product will treat diabetes without adequate substantiation. It still includes the disclaimer, and the FTC says the ad is deceptive anyway, because the disclaimer does not negate an explicit claim.

The guidance also warns advertisers not to mischaracterize the extent to which a product or claim has been reviewed or approved by the FDA. It says following the DSHEA notification and disclaimer provisions is not FDA authorization, and that advertisers should not imply the FDA has approved a claim on that basis. Some of our reviews flag "FDA approved facility" wording. See the ProDentim review for an example, where the finding is that the FDA registers supplement facilities but does not approve them.

Vague qualifiers do not help either. The guidance says words like "may" and "helps" are not enough to convey how limited the science is, and that consumers tend to read "promising" or "preliminary" as positive rather than as a warning. In one example, "promising, preliminary scientific studies show that our product may be effective" is unlikely to convey the limits of two weak studies.

How can you use these rules when you read a sales page?

You cannot judge legality from the outside, but you can borrow the questions the FTC asks. Use this checklist:

1. Find the exact health claim, including the ones implied by images, stories and doctor coats.
2. Ask what study supports it, and whether it was randomized, controlled and done in people with the same ingredient at the same dose.
3. Treat customer stories as illustrations, not evidence, especially dramatic ones with small print such as "results not typical."
4. Check who the "expert" is, what qualifies them, and whether they are paid or own part of the company.
5. Look for a plain disclosure when a reviewer earns a commission.
6. Read "FDA" wording literally: registered, approved and evaluated are not the same thing.
7. Compare the label's amounts with the doses used in the studies the page cites.

One example of this in practice is our Nerve Fresh review, which notes that the page credits two different creator doctors and makes an absolute "no side effects" claim. Both are the kind of thing the checklist above would flag for a closer look.

What can you do if an ad looks misleading?

The FDA's supplement page says to contact the FTC to report problematic advertising for a dietary supplement, and the FTC accepts complaints through ReportFraud.ftc.gov. Screenshots, the web address, the date and your order details help. If you already paid, you can ask for a refund separately: our ClickBank refund guide lists the steps.

FAQ

Are before-and-after photos allowed in supplement ads?

The FTC guidance does not ban them, but it treats them as testimonials. The advertiser still needs scientific evidence for the implied claim, and dramatic results need a clear statement of what most people can expect. Small print does not fix a misleading impression.

Does "clinically proven" need a real study?

Under the FTC's approach, yes. An ad must have at least the level of support it claims. If it says "clinically proven," the advertiser needs the evidence to back that specific statement, and the FTC looks at the whole body of research, not one selected result.

Is an influencer allowed to promote a supplement without saying they are paid?

No, if there is a material connection. The Endorsement Guides say a connection consumers would not expect, such as payment or free product, should be disclosed clearly and conspicuously. The FTC adds that a hyperlink alone is easy to miss, and that the disclosure should be unavoidable in social media.

Can a supplement legally claim to treat a disease?

The FDA says a product sold as a supplement and presented for treatment or prevention of a specific disease meets the definition of a drug. Learn to spot that wording, and remember our medical disclaimer: a supplement page is not a substitute for a conversation with your doctor or pharmacist.