Supplement advertising rules: what the FTC requires for claims, evidence and testimonials

Supplement advertising rules in the US come mainly from the FTC: every claim in your ads must be truthful, not misleading and backed by evidence before the ad runs. Under the FTC's 2022 Health Products Compliance Guidance, health claims need competent and reliable scientific evidence, as a general rule randomized, controlled human trials that match your product. Testimonials never count as that proof.

Who enforces supplement advertising rules: the FTC or the FDA?

Both, in different places. Under a memorandum of understanding often called the FDA-FTC Liaison Agreement, the FDA has primary responsibility for claims in labeling and the FTC for claims in all forms of advertising (FTC Health Products Compliance Guidance). Your VSL, your ads, your presell and your emails are advertising. Your bottle and its label are labeling.

Who regulates what

What each covers, and what it asks of you

FTC

All advertising: VSLs, ads, presells, emails

• Truthful, non-misleading claims, with the evidence in hand before they run

FDA

Labels and labeling

• No disease claims
• Structure/function claims carry the disclaimer and a notice to FDA within 30 days of first marketing

Ad platforms and networks

Their own placements

• Their own policies on top of the law (Facebook ads for supplements)

The two agencies differ on procedure, not on proof. FDA rules make supplement marketers notify the agency of structure/function claims; the FTC has no notification step for ads. Both, though, require prior substantiation that a claim is truthful and not misleading. What a supplement may say at all is the FDA's question, and our post on structure/function claims answers it. The rest of this post is the FTC's question: can you prove what your ad says?

How does the FTC decide what your ad claims?

FTC law "focuses not on the marketer's intent, but on the consumer's understanding." The agency weighs the net impression of everything in the ad, and when an ad can reasonably be read more than one way, you need evidence for each reading. Three habits follow:

1. List implied claims, not just spoken ones. The FTC's guidance describes an ad that calls an ointment good for "joint health and mobility" while its pictures show an elderly woman going from a walker to dancing; the images, it says, likely convey a claim about arthritis symptoms. B-roll, product names and testimonials make claims too.
2. Back the level of support you claim. "Clinically tested" implies the tests proved a benefit, not just that tests took place, and you "must have at least the level of support" your ad claims. "Scientists agree" is false unless you can show that scientists really have reached that consensus.
3. Check what buyers take away. The FTC says consumer surveys and copy tests can be valuable for working out how people read an ad's implied claims. Showing the VSL to five people outside your team and asking what it promised is a cheap start.

What is competent and reliable scientific evidence?

Health benefit and safety claims "require substantiation in the form of competent and reliable scientific evidence." The FTC defines it as tests, analyses, research or studies that were conducted and evaluated objectively by experts in the relevant disease, condition or function; that are generally accepted in the profession to yield accurate and reliable results; that are sufficient in quality and quantity by the standards of the field; and that, weighed against the entire body of relevant and reliable evidence, show the claim is true. In practice it comes down to four questions.

Is it a randomized, controlled human trial?

As a general rule, the FTC expects health benefits to be backed by randomized, controlled human clinical testing, which it calls "the most reliable form of evidence." It accepts high-quality epidemiologic evidence only where experts treat it as a substitute and RCTs aren't feasible. Animal and test-tube studies can give useful background, but without confirmation in human RCTs "they aren't sufficient to substantiate health-related claims." Our post on weight loss supplement advertising applies this standard to weight-loss claims.

Is it good research, or just a lot of it?

"Numerous flawed and inadequate studies are unlikely to add up to competent and reliable scientific evidence." Look at how each study was designed, how many people it followed, for how long, and whether the effect was big enough to matter to a buyer. Claims that buyers can't check for themselves, such as most health benefits, are held to a more exacting standard.

What does the rest of the research say?

Studies can't be considered in isolation. Your claim is judged against all the relevant evidence, and if a stronger body of research points the other way, even a carefully qualified claim is likely to be deceptive.

Does it match your product and your buyers?

The FTC asks how the dosage and formulation of your product compare with what was studied, and whether the study population reflects the people your ad targets. An ingredient trial at three times your dose, in another form, in another population, doesn't prove a claim about your capsule.

Here is the difference in practice, for a fictional sleep supplement that says it helps people fall asleep faster:

Evidence behind a supplement claim

Illustrative: a fictional sleep supplement that says it helps you fall asleep faster

Can support the claimAdequate support

• A randomized, placebo-controlled trial of this formula at this dose
• Run in healthy adults like the people the ad targets
• Well controlled, with enough people for long enough
• Consistent with the wider body of research
• A claim that says no more than the trial showed

Does not support itInadequate support

• One ingredient, tested at three times your dose
• Animal or test-tube studies only
• Customer reviews and testimonials
• A trial where the product did no better than placebo
• A pile of small, poorly controlled studies

Keep the studies you rely on where buyers can check them. RevvyScales' scientific references block lists your sources on the page (comments and references), but a reference list isn't substantiation by itself: each study has to support the specific claim it sits beside.

Do testimonials count as evidence?

No. Under the Endorsement Guides, "consumer endorsements themselves are not competent and reliable scientific evidence" (16 CFR Part 255), and the FTC's health guidance adds that "it's not enough that a testimonial represents the honest opinion or experience of an endorser." A hundred real, glowing reviews don't prove a supplement works.

Testimonials also make claims of their own. One about a key benefit is read as what buyers generally get. If you can't show that, the ad has to disclose clearly what buyers generally achieve, and you need evidence for that figure too. The "results not typical" line stopped being a safe harbor when the FTC revised the Guides in 2009 (FTC, 2009). And every testimonial must come from a real customer: the FTC's rule banning fake or false consumer testimonials, AI-generated fakes included, took effect on October 21, 2024 (FTC, 2024).

Our posts on the FTC Endorsement Guides and on before and after photos cover typical-results disclosures in detail.

Can a qualified claim fix weak evidence?

Rarely. The FTC's guidance is blunt:

• "Vague qualifying terms are inadequate." Saying a product "may" deliver a benefit, or "helps" deliver it, doesn't tell buyers the evidence is thin.
• It is "very difficult to adequately qualify a claim based on limited and still-emerging science."
• "If it isn't possible to make an effective disclosure, the claim should be modified."
• A disclosure can't contradict the claim, and it can't rescue a claim that stronger evidence contradicts.

Disclosures still matter where they are the right tool: typical results, the size and length of a study, who a product is for. Make them count:

• Put the disclosure next to the claim, in the same size type. The FTC notes that "disclosures made through hyperlinks are avoidable" and that fine print at the bottom of an ad isn't clear and conspicuous.
• When the claim is spoken and shown, make the disclosure both visual and audible.
• Use numbers, not adjectives.

A fictional example. Weak: "May support deeper sleep*", with the asterisk leading to the page footer. Stronger, if your trial found it and the wider research agrees: "In a 4-week study of 60 adults, people taking the formula fell asleep 9 minutes faster on average than people taking a placebo", shown on screen and spoken when the claim is made. If the disclosure has to sit on the video itself, RevvyScales' video watermark (Growth plan and up) can place a timed image overlay, such as a compliance mark, on the video (watermark).

Traditional use, borrowed articles and "FDA" in your ads

Three shortcuts deserve a second look, and the FTC's guidance addresses each one:

Three shortcuts the FTC's guidance addresses

Traditional useThird-party articlesFDA mentions

Traditional use

"Used for centuries" is a claim about how people used an herb, and buyers may hear it as proof that it works. The FTC "will look closely at how consumers perceive a traditional use claim," and it suggests a copy test or other consumer research to confirm buyers understand the claim's limits.

Third-party articles

DSHEA lets sellers use some third-party literature about an ingredient, under conditions that include reprinting it in its entirety and making sure it isn't false or misleading. The FTC notes that this provision "doesn't provide an exemption from FTC requirements," so an article you show or quote still has to meet the FTC's rules.

FDA mentions

Don't overstate how far FDA reviewed, authorized or approved a product or a claim. Filing a structure/function notice and printing the disclaimer "doesn't constitute FDA authorization," so "FDA-approved formula" is false for a supplement.

What does FTC enforcement against supplement claims look like?

Two actions show how the standard is applied.

Prevagen. In January 2017, the FTC and the New York Attorney General sued the marketers of Prevagen, a memory supplement whose active ingredient is a protein derived from jellyfish. They alleged that claims it improves memory and is "clinically shown" to work were false and unsubstantiated. According to the complaint, the study the company relied on "failed to show that Prevagen works better than a placebo on any measure of cognitive function" (FTC, 2017). In December 2024, after seven years of litigation including a jury trial, the court ordered the maker, Quincy Bioscience, to stop making claims about Prevagen that, in the FTC's words, "mislead Americans concerned about memory loss" (FTC, 2024).

Notices of penalty offenses. In April 2023, the FTC sent notices to about 670 marketers of over-the-counter drugs, homeopathic products, dietary supplements and functional foods. The notice lists practices the FTC has found unlawful, including making health claims without competent and reliable scientific evidence, claiming a product treats a serious disease without at least one well-controlled human clinical trial, and misrepresenting that a product is scientifically or clinically proven. A recipient that engages in those practices can face civil penalties, up to $50,120 per violation at the time, and the FTC stressed that being on the list didn't mean a company had broken the law (FTC, 2023).

Both point the same way: the FTC judges a claim against the evidence you had when the ad ran. For the FDA's side, our review of 16 recent FDA warning letters to supplement firms shows what they cite.

A claim review workflow before launch

Run every VSL, ad and presell through the same five steps before it spends a dollar:

A claim review before launch

1. 1InventoryEvery claim: script, on-screen text, visuals, testimonials, product name, references
2. 2ClassifyFDA: structure/function or disease. FTC: health benefit, safety or other
3. 3Match evidenceHuman RCTs on your formula, dose and audience, checked against all the research
4. 4Rewrite or qualifyCut what you can't prove; put needed disclosures next to the claim
5. 5File and repeatKeep the evidence with the script version; review again after every edit

Most of the work is step 3. Our post on supplement clinical studies shows how to find the research and read it before you build a claim on it:

Keep the output in a claims sheet: time code, claim, express or implied, the evidence on file and the decision. The VSL compliance guide shows an example sheet and covers disclosures and subscription terms. One last check belongs in every review: a DSHEA disclaimer in the footer doesn't change any of the above. The FTC says that disclaimer "won't cure an otherwise deceptive ad."

What to do this week

Start with the VSL that spends the most, then work through the rest:

Supplement ad review: this week

• Transcribe your top-spending VSL and list every express and implied claim
• Write the evidence on file next to each claim, or “none”
• Check each study against your dose, formula and audience
• Remove “clinically proven”, “scientists agree” and similar lines you can't back
• Replace “results not typical” with what buyers generally achieve, if you have the data
• Move key disclosures out of links and footers, next to the claims
• Confirm every testimonial comes from a real customer, with a signed release
• Make sure nothing implies FDA approved the product or a claim

0 of 8 done

Make the same review part of every new ad and every script edit. A claim you can prove is one you never have to pull in a hurry.