FDA responds to CRN’s citizen petition on NAC

The U.S. Food and Drug Administration (FDA) has issued a “tentative response” to a citizen petition submitted by The Council for Responsible Nutrition (CRN; Washington, D.C.) for the agency to reverse its decision to prohibit manufacturers from marketing products containing N-acetyl-L-cysteine (NAC) as dietary supplements. In its response to CRN, FDA simply advised the trade association that it was considering the issues raised by its petition, as well as the petition filed by the Natural Products Association (NPA; Washington, D.C.), but has not yet reached any decision. The agency asked interested parties to submit more data and evidence to help reach a decision such as “data or information regarding the past safe use of NAC in products marketed as dietary supplement.”

CRN’s president and CEO expressed disappointment in FDA’s letter. “FDA’s initial position, expressed in a series of warning letters in July 2020, appears to be that products containing N-acetyl-L-cysteine (NAC) may not be lawfully marketed as dietary supplements. The legal issues here are clear: The provisions of the Dietary Supplement Health and Education Act of 1994 (DSHEA) may not be interpreted retroactively to remove ingredients that were lawfully marketed in 1994 and have enjoyed a long history of safe use since then. The delay in clearing up the status of NAC by asking for more data and refusing to admit its error disregards the law and disserves consumers who use NAC,” says Mister in a statement.

“This is not a complicated determination for FDA to make. DSHEA makes clear that ingredients in use as dietary supplement ingredients prior to its enactment are grandfathered into the supplement marketplace. Thus, pharmaceutical manufacturers could not have had any expectation of exclusivity in the years prior to the creation of this provision of the law,” Mister continues. “Given the long history of safe use of NAC, FDA cannot now try to establish a safety concern in order to award this ingredient exclusively to drug makers. Even members of Congress have expressed concerns over FDA’s position on NAC while the agency continues to avoid admitting its error in the warning letters.”

As a result of the warning letters, says Mister, many retailers have discontinued the sale of NAC products, hurting the ability of consumers to access these products. “FDA’s delay is a disservice to the dietary supplement industry, retailers, health care practitioners, and most importantly, the more than 200 million supplement users who rely on FDA to do its job,” Mister concludes.