Structure/function vs. disease claims: what underwriters flag
One sentence on a product page can turn a legal supplement into an unapproved drug, as far as regulators and banks are concerned. Here's where the line sits, where disease claims hide, and what an underwriter looks for before approving a supplement merchant account.
The difference between structure/function and disease claims
A structure/function claim describes how a nutrient or ingredient affects the normal structure or function of the body. "Calcium builds strong bones" and "fiber maintains bowel regularity" are classic examples. Supplements can make these claims without FDA approval.
A disease claim says, outright or by implication, that a product diagnoses, treats, cures, mitigates or prevents a disease. Under 21 CFR 101.93, a supplement that makes one is regulated as a drug, and selling an unapproved drug is illegal. That's the point where payment risk starts: banks and card networks don't process sales they consider illegal.
Structure/function claims come with two conditions. The label must carry this disclaimer, next to the claim or linked to it with an asterisk:
And the company must notify the FDA within 30 days of first marketing a product with the claim. The FDA doesn't approve the claim. It usually replies only if it objects.
Structure/function vs. disease claim examples
Small wording changes move a claim across the line. Most of these pairs come straight from the FDA's own structure/function compliance guide.
The FTC asks a different question: can you prove it?
The FDA regulates labels. The FTC regulates advertising, and it doesn't care whether a claim is labeled structure/function or not. Its Health Products Compliance Guidance applies one standard to every health claim.
- Competent and reliable scientific evidence. As a general rule, that means well-designed human clinical trials, with results that matter in real life, not just statistically.
- Ingredient studies may not be enough. A trial on one ingredient at one dose doesn't automatically prove your blend works.
- "Clinically proven" means proven. Overstating the level of evidence is a claim in itself.
- Vague hedges don't fix weak claims. The FTC says words like "may" or "helps" aren't enough to qualify a claim the evidence doesn't support.
The FTC has been explicit about this. In April 2023 it sent notices to about 670 companies, including supplement marketers, warning that unsupported health claims could bring civil penalties. Its rule on fake reviews and testimonials has applied since October 21, 2024.
What underwriters check, and how they rate it
For a nutraceutical merchant account, the underwriter reviews your website, label images, checkout and marketing, and often searches for regulatory actions against the company and its owners. Here's how we sort what we find in a pre-review.
- Explicit disease claims: cures, treats or prevents a named disease
- Ingredients the FDA treats as drugs, or has warned about
- "FDA approved" or any suggestion of FDA review
- Claims that the product replaces a prescription
- Implied claims in product names, images or study citations
- Featured reviews or affiliate pages with disease language
- "Clinically proven" without a study on the product
- Missing or misplaced FDA disclaimer
- Normal-function language throughout, with the disclaimer in place
- Labels that match the website and the certificates of analysis
- Ads, emails and affiliate pages that say the same as the product page
How to clean up your claims before you apply
List every place you make a claim
Labels, product pages, image alt text, ads, emails, social posts, influencer content and affiliate pages. The underwriter will look at all of it.
Rewrite to normal function
Replace disease words with normal-function language, and add "already in the normal range" where a claim touches a measurable level.
Check names, images and citations
Rename products that reference a condition, swap out disease imagery, and move study links into a balanced references section.
Place the disclaimer correctly
Put it next to each claim or link it with an asterisk. If it isn't adjacent, set it off in a box, on every panel or page that has a claim.
File and document
Send the FDA notification within 30 days of first marketing a claim, and keep a file of the evidence behind each one.
Brief your partners
Give affiliates and influencers approved claim language in writing, and check their pages before you apply and regularly after.
This is a general overview, not legal advice. A regulatory lawyer should review your final claims.
Supplement claims FAQs
Does the FDA disclaimer protect me if I make a disease claim?
No. The disclaimer goes with structure/function claims. It says the product isn't intended to treat disease, so placing it next to a disease claim contradicts it and doesn't change how the claim is read.
Do I need FDA approval for a structure/function claim?
No. You need to notify the FDA within 30 days of first marketing the claim, carry the disclaimer, and have evidence that the claim is truthful and not misleading.
Am I responsible for what customers say in reviews?
Reviews you choose to feature in ads, emails or product pages can be treated as your own marketing claims. Don't promote testimonials that mention diseases, and don't suppress honest negative reviews, which the FTC's reviews rule also prohibits.
Can I say my supplement is "clinically proven"?
Only if well-designed human trials support that specific benefit for your product, or an equivalent formula at the same dose. A study on one ingredient usually isn't enough for a blend.
Will an old FDA warning letter stop my application?
Not necessarily. Underwriters want to see what the letter said, how you responded and what changed. A clear written explanation, with your corrected pages, makes a real difference. For more complex histories, a high-risk merchant account may be the better route.
Not sure about your claims? Find out before an underwriter does.
Send us your product pages, labels and ads. A DMS specialist will flag the claims an underwriter is likely to question and tell you what to change before you apply.