VITAMINS & SUPPLEMENTS · GUIDE
Structure-Function Claims vs Disease Claims and the FDA Disclaimer
How US supplement claims are sorted into structure-function, health, nutrient-content and disease claims, what the FDA disclaimer means, and why a claim on a label is not proof it works.
Content last updated . This page has not been medically reviewed.
Back to Supplement FormulasThis page describes US rules as FDA describes them. Other countries are not described in the sources we read; see supplement regulation by country.
The claim types
The FDA labeling guide used here is from 2005 and is nonbinding, so check current rules if a decision depends on them.| Claim type | Plain meaning (FDA wording) | Before use? | Disclaimer? |
|---|---|---|---|
| Structure/function | The role of a nutrient or ingredient intended to affect the normal structure or function of the body, such as "calcium builds strong bones" [2] | Not pre-approved; the maker needs substantiation that it is truthful and not misleading [2] | Yes [1] |
| General well-being | Describes general well-being from consuming an ingredient [2] | Same as above [1] | Yes [1] |
| Nutrient deficiency disease | A benefit related to a deficiency disease, such as scurvy, allowed only with a statement of how widespread it is in the US [2] | Same as above [1] | Yes [1] |
| Health claim | A relationship between a substance and reducing the risk of a disease, such as "calcium may reduce the risk of osteoporosis" [3] | Requires FDA evaluation and authorization [3] | Qualified health claims carry a statement of the level of evidence [3] |
| Disease claim (treat, cure, prevent) | Makes the product a drug [1] | Not allowed on a supplement | Not applicable |
A qualified health claim is supported by less scientific evidence than an authorized one. [3] FDA points to its rule 21 CFR 101.93 for the difference between structure/function claims and disease claims. [2] We did not read that rule itself, so we do not give examples of where the line falls.
What the disclaimer says and requires
The disclaimer says FDA has not evaluated the claim and that the product is not intended to "diagnose, treat, cure, or prevent any disease." [3] FDA says a disease can only be addressed by a drug, which is why the sentence is required. [2] The wording may not be changed. [3] It must sit right next to the claim, or in a box on the same panel linked by a symbol. [3] A maker must notify FDA within 30 days of first marketing a product with such a claim. [3]What that means in practice: By law FDA does not approve dietary supplements or their labeling. [1] It also says that for structure/function claims, the maker must have substantiation. [2] That substantiation is not published on the label, and the sources we read do not say how strong it has to be.
Who oversees advertising
FDA says it is generally responsible for safety, quality and labeling, and the Federal Trade Commission for advertising. [1] So a claim in an online ad, an influencer video or a store sign is judged under advertising rules, not by the label disclaimer.What research says about supplement claims
| Question | What the source reports | Strength of evidence |
|---|---|---|
| Do ingredients in "immune support" products have good human evidence? | NCCIH reports a 2022 review of 27 common ingredients that found rigorous human studies for only eight of them [4] | Summary of a review; we did not read the review itself |
| Are claims always legal? | NCCIH reports a 2012 government study of 127 weight-loss and immune supplements in which 20 percent made illegal claims [4] | Summary of one study; older data |
NCCIH also says strong evidence behind supplement claims is often lacking. [4] For a specific product's claim, "Proper evidence not found" is the honest default until you see trials of that product, its ingredients, amounts and people like you.
"High potency" and similar words
FDA's guide says "high potency" may be used for an individual vitamin or mineral present at 100 percent or more of the RDI per reference amount customarily consumed. [3] It describes the amount on the label, not benefit or safety, and a high amount can raise safety questions; see high-potency and megadose multivitamins.Frequently asked questions
What does "This statement has not been evaluated by the FDA" mean?
It is the required disclaimer on structure/function claims and similar claims. It tells you FDA has not evaluated the claim. [1]
Can a supplement claim to treat or cure a disease?
No. A product represented for treatment, prevention or cure of a specific disease meets the definition of a drug. [1]
What is a structure/function claim?
A claim about the role of a nutrient or ingredient in the normal structure or function of the body, for example "calcium builds strong bones." [2]
Does FDA approve supplement claims?
Not structure/function claims. Health claims need FDA authorization. [3]
Does the disclaimer mean the supplement is unsafe?
No. It means the claim has not been evaluated by FDA. [1] Safety questions are separate; ask a clinician or pharmacist.
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Safety and next steps
- A claim on a label does not mean the product is safe with your medicines, pregnancy, kidney or liver disease or upcoming surgery. FDA advises talking to a doctor, pharmacist or other health care professional before using a supplement. [1] See medication interactions.
- Treat words like "cure," "treats" or "prevents" a disease on a supplement as a red flag; see label red flags.
- Never stop or change a prescribed treatment because of a supplement claim; ask the prescriber.
References
- FDA: Questions and Answers on Dietary Supplements (content current 27 Aug 2026). Read 2026-10-23.
- FDA: Structure/Function Claims (content current 28 Mar 2024). Read 2026-10-23.
- FDA: Dietary Supplement Labeling Guide, Chapter VI Claims (April 2005, nonbinding). Read 2026-10-23.
- NCCIH: Using Dietary Supplements Wisely. Read 2026-10-23.