Your supplement can't treat anything. Not in a label, not in an ad, and not in your newsletter.
But it can support, maintain, and promote. That's the structure/function claim guardrails, the legal lane most women's health brands sell in. Here’s how to make sure you don’t cross that line.
Every email I write for clients goes through a claims review before it's scheduled. Learn more about my process here.
What is a structure/function claim?
A structure/function claim describes how a nutrient or ingredient affects the normal structure or function of the body. The FDA's own examples: "calcium builds strong bones" and "fiber maintains bowel regularity." (1)
Notice what those sentences don't say. They don't mention a disease, a diagnosis, or a symptom of one. They describe the body doing its normal job, with a little help.
Structure/function claims exist because of a 1994 law, the Dietary Supplement Health and Education Act (DSHEA). It lets supplements make these claims without FDA pre-approval, on three conditions (1, 2):
The claim is truthful and not misleading
The label carries the FDA disclaimer (more on that below)
The company notifies the FDA within 30 days of first marketing the product with that claim
The key word is normal. The moment a sentence implies your product fixes something that's gone wrong, you've left structure/function territory.
Structure/function claim vs health claim vs disease claim: what's the difference?
The FDA has three buckets, and they get mixed up constantly. Even by people who should know better. A structure/function claim describes normal body function. A health claim links a substance to a reduced risk of a disease and needs FDA authorization. A disease claim says a product treats, cures, mitigates, or prevents a disease, and only a drug can legally make one. (1, 2)
Structure/function claim: How an ingredient supports normal body function. Example: "Supports healthy digestion." No FDA approval needed, but it needs the disclaimer and the 30-day notice. Can go in your email, with evidence behind it.
Health claim: A substance–disease risk relationship. Example: calcium and reduced risk of osteoporosis. Needs FDA authorization (authorized or qualified). In your email, only the exact authorized wording.
Disease claim: Product treats, cures, mitigates, or prevents a disease. Example: "Relieves IBS." Not allowed for supplements, in email or anywhere else.
When people say "you can't make health claims," they usually mean disease claims. Health claims are a narrow, pre-approved category. Most brands will never write one, and you shouldn't improvise one.
Do supplement rules apply to my marketing emails?
Yes, through two agencies at once. The FDA rules on structure/function claims are written for labels and labeling. But FDA regulations say a product's intended use can be shown by "advertising matter" and "written statements" from the company (3). Your emails count as evidence of what you're selling the product to do.
Then there's the Federal Trade Commission. The FTC's Health Products Compliance Guidance, published in December 2022, applies to health advertising in any medium, email included (4, 5). The FTC standard is "competent and reliable scientific evidence," and for most health benefit claims it expects high-quality randomized controlled trials in people (4).
So an email has two jobs:
Stay in the structure/function lane (FDA)
Be able to prove what you said (FTC)
A compliant-sounding claim with no evidence behind it fails the second test. "Supports deep sleep" is structure/function language. If you can't show that your ingredient, at your dose, supports deep sleep in humans, it's still a problem.
What can I say about menopause, PMS, and other women's health symptoms?
More than most women's health brands think. This is where I see brands get either reckless or so scared they say nothing at all.
The regulation (21 CFR 101.93) defines a disease as damage to an organ or body system so it doesn't function properly, or a state of health leading to that (2). Natural life stages like menopause, the menstrual cycle, and pregnancy aren't diseases.
The rule's dividing line for conditions tied to those natural stages: a claim about one becomes a disease claim if the condition is uncommon or can cause significant or permanent harm (2). Common, non-dangerous experiences of a normal life stage are a different category from conditions that need a doctor.
In practice, that means there's a real difference between:
Occasional, common experiences tied to a normal life stage
Named conditions that need a diagnosis (endometriosis, PCOS, osteoporosis, clinical depression)
The second group is disease territory.
Your reader won't post about her menopause rage. She may not even bring it up with her doctor. But she'll open your email about it. That's exactly why the wording has to be right.
Five places disease claims sneak into emails
The 101.93 rule doesn't only look at the words "treats" and "cures." It lists ten ways a statement can become a disease claim (2). Five of them show up in email constantly.
Subject lines and preview text
A subject line is a claim. "Finally, relief from your IBS" is a disease claim even if the email body is spotless. Subject lines get written last and fast, which is exactly why they slip.
Customer testimonials
When you put a customer's words in your email, they're your claim now. The FTC's Endorsement Guides say an endorsement can't convey a claim the advertiser couldn't make directly (6). "This cured my PCOS" in a testimonial block is your company saying it.
Linking or naming a study
Citing a publication that's about a disease use counts, if the context implies your product treats or prevents it (2). Linking "Magnesium and Migraine Prevention: A Randomized Trial" right under your magnesium product is a disease claim by association.
Product and program names
A name can make the claim on its own (2). "Thyroid Rescue" or "Candida Cleanse" says something the label copy isn't allowed to.
Images, symbols, and before-and-afters
The regulation includes "pictures, vignettes, symbols" (2). A photo of an inhaler next to your lung-support formula. A heart-rate monitor graphic. The words are fine and the picture isn't.
Disease claims rewritten as structure/function claims
Most disease claims can be rewritten. Shift from fixing a problem to supporting normal function, and drop the condition name. Here are common ones I see in women's health and supplement emails, with a structure/function version that keeps the benefit.
Lowers cholesterol → Supports cholesterol levels already within a normal range
Prevents UTIs → Supports urinary tract health
Treats anxiety → Promotes a calm, relaxed mood
Fights infections → Supports healthy immune function
Reverses insulin resistance → Supports healthy blood sugar levels already within a normal range
Heals leaky gut → Supports the gut lining's normal function
Does the FDA disclaimer make it OK?
No. The FDA disclaimer is required with a structure/function claim. It doesn't protect a disease claim. The exact wording in 21 CFR 101.93 is (2):
"This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease."
Read the second sentence again. The disclaimer literally says your product isn't intended to treat disease. Putting it under "heals your thyroid" doesn't cancel the claim. It contradicts it, in writing, in your own email.
Many brands put the disclaimer in their email footer. The rule is written for labels, so whether and where you need it in email is a question for your regulatory counsel. Either way, it's a floor, not a shield.
A pre-send check for structure/function claims
Before any supplement or wellness email goes out, I run it through four questions. You can use the same four.
Does any sentence name a disease or a diagnosis? Check the subject line, preview text, testimonials, P.S., and image alt text, not only the body.
Does it describe fixing something broken, or supporting something normal? "Restores" and "repairs" are red flags. "Supports" and "maintains" are your lane.
Can you show evidence for this ingredient at this dose? If the honest answer is "the ingredient has been studied," that's not the same thing.
Would a reader reasonably take it as a promise to treat a condition? The FTC judges the net impression, not your intent.
If a sentence fails any of them, rewrite it before it's scheduled. Not after a complaint.
Claims I’ve seen made time and again by well-meaning brands:
Boosts libido
Cures vaginal dryness
Stops urinary leaks
This isn't legal advice. I'm a marketer who's spent nearly ten years writing inside clinician-led health brands, not an attorney. For your specific products, your regulatory counsel has the final word.
FAQ
What is an example of a structure/function claim?
"Calcium builds strong bones" and "fiber maintains bowel regularity" are the FDA's own examples (1). Both describe a nutrient supporting normal body function without mentioning a disease.
What are qualified health claims?
Qualified health claims link a substance to reduced disease risk when the evidence is still emerging. They have to be reviewed through the FDA and use specific qualifying language that tells the reader the evidence is limited (7). Supplement brands can't write their own.
Do I need the FDA disclaimer in every email?
The disclaimer requirement in 21 CFR 101.93 is written for product labels (2). Many brands include it in email footers anyway. Ask your regulatory counsel what your setup requires. It doesn't make a disease claim compliant either way.
Can a customer review say a product helped her condition?
Not in your marketing. If you feature it, it's your claim, and an endorsement can't say what you couldn't say directly (6).
Who enforces claims in supplement emails?
Both the FDA and the FTC. The FDA looks at whether you're marketing a supplement as a drug. The FTC looks at whether your advertising claims are truthful and backed by evidence (3, 4).
The House Call
Every email I write for clients gets a claims review before it's scheduled. Weekly emails in your voice, flows that keep earning, and nothing goes out that you'd lose sleep over. Learn more about the House Call.
References
U.S. Food and Drug Administration. Structure/Function Claims. Content current as of March 28, 2024. https://www.fda.gov/food/nutrition-food-labeling-and-critical-foods/structurefunction-claims
21 CFR 101.93 — Certain types of statements for dietary supplements. Legal Information Institute, Cornell Law School. https://www.law.cornell.edu/cfr/text/21/101.93
21 CFR 201.128 — Meaning of "intended uses." https://www.law.cornell.edu/cfr/text/21/201.128
Federal Trade Commission. Health Products Compliance Guidance. December 2022. https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance
Covington & Burling. FTC Issues New Guidance on Health-Related Claims to Replace the Dietary Supplements Advertising Guide. January 2023. https://www.cov.com/en/news-and-insights/insights/2023/01/ftc-issues-new-guidance-on-health-related-claims-to-replace-the-dietary-supplements-advertising-guide
16 CFR Part 255 — Guides Concerning the Use of Endorsements and Testimonials in Advertising. https://www.ecfr.gov/current/title-16/chapter-I/subchapter-B/part-255
U.S. Food and Drug Administration. Qualified Health Claims. https://www.fda.gov/food/food-labeling-nutrition/qualified-health-claims