The U.S. Food and Drug Administration (FDA) denied the request in two citizen petitions, from the Council for Responsible Nutrition (CRN) and the Natural Products Association (NPA), asking the agency to determine that products containing N-acetyl-L-cysteine (NAC) are not excluded from the definition of a dietary supplement under section 201(ff)(3)(B)(i) of the Federal Food, Drug, and Cosmetic Act (FD&C Act).
While the FDA’s response to the citizen petitions confirmed NAC is excluded from the definition of a dietary supplement, the agency has not yet reached a decision on the NPA citizen petition’s alternative request that the agency undertake rulemaking to allow the use of NAC in dietary supplements. The FDA continues to review this request.
In the interim, in light of the absence of safety concerns based on FDA’s review to date, among other factors, the FDA is considering exercising enforcement discretion for NAC-containing products labeled as dietary supplements that would be lawfully marketed dietary supplements if NAC were not excluded from the definition of dietary supplement and are not otherwise violative of the FD&C Act. The FDA intends to issue guidance about its policy on NAC-containing products labeled as dietary supplements in the near future.