Washington, D.C.—The U.S. Food and Drug Administration (FDA)announced in a Constituent Updatethat it is issuing  “Policy Regarding N-acetyl-L-cysteine: Draft Guidance for Industry” to be published on April 22, 2022. FDA said the draft guidance, when finalized, will explain the agency's intent to exercise enforcement discretion with respect to the sale and distribution of certainNAC-containing products that are labeled as dietary supplements. FDA added that the enforcement discretion policy would apply to products lawfully marketed dietary supplements if NAC were not excluded from the definition of “dietary supplement” and are not otherwise in violation of the Federal Food, Drug, and Cosmetic Act (FD&C Act).

The move comes after FDA announced on March 31, 2022 that it had denied the request in citizen petitions from theCouncil for Responsible Nutrition (CRN)andNatural Products Association (NPA)that asked the agency to determine that products containing NAC are not excluded from the definition of a dietary supplement—but the agency added that it was still reviewing an alterative request outlined in NPA's citizen's petition calling on the agency undertake rulemaking to allow the use of NAC in dietary supplements.

In its April 21 update, FDA said: "While our full safety review of NAC remains ongoing, our initial review has not revealed safety concerns with respect to the use of this ingredient in or as a dietary supplement. In addition, NAC-containing products represented as dietary supplements have been sold in the United States for over 30 years and consumers continue to seek access to such products. Accordingly, while the FDA continues its evaluation of the request to initiate rulemaking, the FDA issued this draft guidance to explain our policy regarding products labeled as dietary supplements that contain NAC." Unless safety-related concerns are identified during the review, FDA said it would intend to exercise enforcement discretion.
Background: FDA Response on NAC Sets “Dangerous Precedent”
NPA shared news that the FDA's enforcement discretion details that no restrictions on daily amounts of NAC by the Agency were part of the guidance document. NPA added that the association had anticipated this, given NAC’s extensive safety record dating back more than 30 years.

“We’re glad we won this round, but we’re not glad we had to go to such great lengths to secure this for American consumers and a functioning regulatory regime," said Daniel Fabricant, Ph.D., President and CEO of the NPA, which had filed a Citizen’s Petition and lawsuit against over NAC. "FDA could have and should have reached this decision years ago, but I credit NPA’s members for realizing what was at stake and being committed to this extraordinary effort."

Also commenting on FDA's action, CRN President & CEO Steve Mister said, "CRN appreciates FDA’s quick action following its March 31 response to ourcitizen petitionwith the announcement of this draft guidance today. We thank FDA for realizing that retailers and marketers of NAC need clarity and certainty in the market and assurance from the agency that there are no known safety concerns with these products. We hope today’s announcement by FDA provides retailers, payment platforms, and product marketers with the assurance they have been asking for—that they may continue to sell NAC-containing dietary supplements without threat of FDA enforcement action. We are grateful for the agency’s statements that it is not aware of any safety-related concerns with NAC. CRN looks forward to working with our retail partners and other stakeholders in continuing to assure consumers have access to otherwise lawful dietary supplements containing NAC."

Both CRN and NPA expressed ongoing concerns.

"CRN also continues to express our disagreement with FDA’s reasoning that led to this announcement," Mister said. "We believe FDA’s overly expansive interpretation of the drug preclusion provision in the federal Food, Drug & Cosmetic Act [21 USC § 321(ff)(3)(B)] and retroactive application of the clause are misplaced and set a dangerous precedent for the agency to remove other lawful dietary ingredients from the market based on assertions of pre-1994 drug approvals or clinical investigations. Without consideration of routes of administration, dosage/serving levels, biological mechanisms of action, or the intended uses of the products, FDA would allow drug manufacturers to remove safe and beneficial dietary supplements from consumers using decades old research to get a monopoly for their pharmaceuticals. We continue to evaluate our options to revise the statute to clarify the original intent of the drug preclusion provision.”

NPA commented that, while this is a positive and critical first step, there is more work to do. "We still see dark clouds on the horizon," Dr. Fabricant said. "Citizen's petitions and lawsuits should be the exception and not the rule, but FDA’s inaction onCBDis very similar to the NAC discussion. We also see greater risk of this happening on a widespread scale if efforts to pass unnecessary and unwise product listing requirements throw more sand in the gears of timely agency proceedings. The industry has experienced significant economic harm as a direct result to the Agency’s actions on NAC. Hadmandatory product listingbeen in place at the time of FDA’s action, we are confident the economic harm would have been more significant than it already has been for industry stakeholders who provide millions of consumers with NAC. We have to find a remedy to other actions that have adversely impacted the NAC market, specifically the denial of export certificates and thedelisting of NACfrom certain e-commerce platforms.”

In light of FDA's announced policy on NAC enforcement discretion, NPA will be hosting a webinar, titledA Regulatory Update for NAC, on April 26, 2022. NPA members and other interested parties can attend the webinar for share insights and analysis.
Related: The Natural View: Regulatory Update with NPA’s Kyle Turk Industry Reacts to FDA FY 2023 Budget Request; Proposal to Modernize Dietary Supplement Regulation