What can you say about N-acetylcysteine (NAC) in your ads and on your site?

The library gives no supported wording for N-acetylcysteine (NAC), because every claim about it is flagged for review. Avoid wording that names or implies a disease, a drug or a treatment, such as “Treats PCOS, or restores ovulation in PCOS”.

Also called: NAC, N-acetyl-L-cysteine, N-acetylcysteine, Acetylcysteine

Reviewed 15 October 2026

Not legal advice. This guide shows the wording that published evidence supports at a daily dose, from the sources linked below; it is not a ruling on any claim. Your own product, its form and dose, and your own evidence still need to match the wording you use.

Flagged for review. FDA, as of 1 May 2026: NAC is excluded from the definition of dietary supplement under section 201(ff)(3) of the FD&C Act, and FDA’s guidance of August 2022 says it will use enforcement discretion for products that would be lawful dietary supplements if NAC were not excluded.

Supported wordings

What you can say.

Claims Facts

No supported wording yet.

Every NAC claim is flagged for review because of FDA’s position on NAC as a dietary ingredient (library decision of 2026-10-15; see review_flag), so the library gives no supported wording for it. Health Canada’s antioxidant use is kept as a note.

Wordings to avoid

What to leave out.

Claims Facts

Ingredient: N-acetylcysteine (NAC)

Wording to avoid	Reason
“Treats PCOS, or restores ovulation in PCOS”Names a disease (polycystic ovary syndrome).	Disease
“Detoxes or protects the liver”Promises to treat or protect an organ from damage.	Treatment
“Treats depression, OCD or addiction”Names diseases.	Disease
“Breaks up mucus, or treats bronchitis or COPD”Names diseases and describes a drug action.	Disease

Disease: names or implies a disease. Drug: names a drug or presents the product as one. Treatment: promises to treat, cure or prevent a condition.

Sources

Where this comes from.

All ingredient guides

Check the claims on your own site. Free.

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