NPA files citizen petition for reversal of FDA policy on N-acetyl-L-cysteine

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The Natural Products Association (NPA, Washington, D.C.) has filed a citizen petition arguing for the reversal of the U.S. Food and Drug Administration’s (FDA) position that the Federal Food, Drug, and Cosmetic Act (FDCA) prohibits manufacturers from marketing products containing N-acetyl-L-cysteine (NAC) as dietary supplements. FDA asserts in multiple warning letters that products containing NAC cannot be marketed as dietary supplements because the ingredient was approved as a new drug in 1963, and there are no records of NAC being marketed as a dietary supplement prior to that date.

NPA asserts in its petition that the records FDA is basing this decision on are not reliable, and that the new policy is a reversal of longstanding FDA policy and contradicts prior FDA decisions on the ingredient. On the evidence of NAC’s approval as a new drug, Daniel Fabricant, PhD, president and CEO of NPA states in the petition: “I am aware from first-hand experience while leading the Agency’s dietary supplement program that documents of the type FDA is relying on to determine the date NAC was first approved as a new drug are questionable at best, and oddly not posted at the time of the 2020 warning letters. Usually, evidence from the period of time in question are handwritten notes and documents. There are often gaps in the record and the information available can be both unverifiable and unreliable.”

Furthermore, the specific forms and indications of the approved NAC drug article was as an intravenous injectable for acetaminophen overdose and as an inhalational drug for bronchopulmonary disease. The petition states that while it is clear under Section 201 (ff)(2) of the Act that an article must be intended for ingestion for it to meet the definition of a dietary supplement, it is less clear whether the language provided in Section 201(ff)(3)(B)(i) of the Act calls for an article’s exclusion from the definition of dietary supplement when the article that has been approved as a drug is not intended for administration by ingestion.

Despite its current position, NPA points out in its citizen petition that in 2018, in response to a petition for a qualified health claim (QHC) by Sevo Nutraceuticals, FDA affirmed that NAC was a lawful component of food or dietary supplements. A response to a QHC petition is considered a final agency action, says the petition, while warning letters are generally not. FDA’s new position on NAC also ignores the long history of products safely marketing the ingredient. For example, the petition cites an advertisement that clearly indicates NAC was marketed in October of 1993, a full year before the effective date of DSHEA. This means the provision FDA is using to determine NAC is excluded from the definition of dietary supplement did not exists at the time NAC was first marketed as a dietary supplement.

“The Food and Drug Administration has not established a public health risk for NAC,” said Fabricant in a press release. “Not only has NAC been used safely in products pre-DSHEA, but it is also a common amino acid that’s found in food we eat every day like onions and garlic. We are continuing to tell our members to sell the product directly, and today’s action is another signal to the FDA that we are going to stand up for the industry and consumers’ access to safe and well-regulated supplements.”

Prior to this, CRN submitted its own citizen petition, asserting much of the same arguments against FDA’s position on NAC.