Quick answer
A structure/function claim is a label statement about how a nutrient or dietary ingredient affects the normal structure or function of the body. Supplement makers may use one without FDA approval, but must hold evidence that it is truthful, notify the FDA within 30 days of marketing, and print the FDA disclaimer.1,2
Key facts
- The claim may describe a nutrient's role in a structure or function of the body, or the documented mechanism by which it acts to maintain that structure or function.2,3
- Two related types follow the same rules: claims of general well-being, and claims about a classic nutrient deficiency, which must also say how common that deficiency is in the United States.1,4
- FDA does not approve these claims before use; the company must have substantiation that the claim is truthful and not misleading.1,4
- The notice to FDA gives the claim's text, the ingredient and the product, and is signed by someone who certifies the firm has substantiation.2
- Conventional foods can carry structure/function claims too, without the notice or the disclaimer.1
Three kinds of label claim
| Claim type | What it describes | FDA review before use |
|---|---|---|
| Structure/function | A nutrient or ingredient's role in normal body structure or function | None; a notice within 30 days and the disclaimer |
| Health claim | A link between a substance and a lower chance of an illness or health related condition | Yes; an authorizing regulation, or an FDA letter for a qualified claim |
| Nutrient content claim | The level of a nutrient, in words such as high, low or free | Must meet FDA's definitions for those words |
Where the line falls matters. A statement about maintaining normal structure or function is allowed, but a claim to act on an illness makes the product a drug in the eyes of the law, unless it is an authorized health claim the product qualifies for.2,4
What the company must do
- Hold substantiation that the claim is truthful and not misleading.3,6
- Notify FDA no later than 30 days after first marketing the product with the claim, giving the claim's text, the ingredient and the product's name.2
- Print the disclaimer in bold type at least 1/16 inch high, next to the claim or linked to it by a symbol such as an asterisk.2
There is no official form for the notice; a letter with the required information is enough. FDA reviews these notices after marketing begins, and the Federal Trade Commission oversees claims in advertising.4,6
Where the line is drawn
Under 21 CFR 101.93, a disease is damage to an organ, part, structure or system of the body such that it does not function properly, or a state of health leading to that, with classic nutrient deficiency diseases such as scurvy set apart. A statement is a disease claim if it says, outright or by implication, that a product diagnoses, mitigates, treats, cures or prevents a disease.2
- Saying the product affects a specific disease or class of diseases.2
- Saying it affects the characteristic signs or symptoms of a disease, in scientific or everyday words.2
- Implying a disease effect through the product's name, pictures or symbols, or the publications it cites.2
- Presenting it as a substitute for a therapy, or as an add on to a drug treatment.2
A product sold as a dietary supplement and represented for the treatment, prevention or cure of a specific disease is regulated as a drug.4
Questions people ask
Does FDA check structure/function claims?
Not before they are used. FDA receives a notice with the claim's text but does not approve it, which is why the label must say the statement has not been evaluated by the Food and Drug Administration.1,4
How is a structure/function claim different from a health claim?
A health claim links a substance to a lower chance of an illness and needs FDA authorization first. A structure/function claim describes a role in normal body structure or function and needs no authorization, only substantiation, a notice and the disclaimer.5,6
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Sources
- U.S. Food and Drug Administration. Structure/Function Claims. Content current as of March 28, 2024. Opened 2026-10-07.
- Code of Federal Regulations, Title 21, Section 101.93: Certain types of statements for dietary supplements. Legal Information Institute, Cornell Law School (eCFR text). Opened 2026-10-07.
- United States Code, Title 21, Section 343: Misbranded food (paragraphs r(6), s and w). Legal Information Institute, Cornell Law School. Opened 2026-10-07.
- U.S. Food and Drug Administration. Questions and Answers on Dietary Supplements. Content current as of August 27, 2026. Opened 2026-10-07.
- U.S. Food and Drug Administration. Label Claims for Conventional Foods and Dietary Supplements. Content current as of March 28, 2024. Opened 2026-10-07.
- U.S. Food and Drug Administration. Dietary Supplement Labeling Guide: Chapter VI. Claims. April 2005. Opened 2026-10-07.
This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.