CRN action on NAC

CRN is working to protect consumer access to N-Acetyl-L cysteine (NAC) dietary supplement products following fallout from FDA’s announcement in July 2020 via warning letters that it does not consider NAC to be a legal dietary ingredient. 

AUGUST 1, 2022: FDA today announced the availability of a final guidance on its policy regarding products labeled as dietary supplements that contain N-acetyl-L-cysteine (NAC).  The guidance explains the agency's intent to exercise enforcement discretion with respect to the sale and distribution of certain NAC-containing products that are labeled as dietary supplements. 

  • “This enforcement discretion policy applies to products that would be 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).”



APRIL 21, 2022: CRN responds to FDA draft guidance

  • CRN welcomes FDA's April 21 draft guidance on NAC to provide retailers, payment platforms, and product marketers with the assurance they have been asking for—that they may continue to sell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 enforcement. But clarity on the agency's broader interpretation of the drug preclusion provision is needed going forward. Read more in our press release.

MARCH 31, 2022:

IN THE NEWS—Read up on stakeholders' responses to FDA's decision:

MARCH 14, 2022: DOJ filing in NPA's lawsuit

MARCH 2, 2022: FDA letter to CRN 

JAN. 26, 2022: CRN Files Comments with FDA, Calls for Swift Agency Response to Citizen Petition on NAC Status

JAN. 4, 2022: CRN Criticizes FDA’s ‘Nonresponsive’ Response to Citizen Petition on NAC

NOV 24, 2021: FDA response letter

NOV 17, 2021: CRN Disappointed With FDA Response to NAC Citizen Petition

Get Involved: Contact your member of Congress and FDA

Recent background:

CRN's Megan Olsen discussed NAC during "Short legal briefs, with Josh Long" on the SupplySide365 Network. WATCH HERE.

“CRN is firmly committed to protecting our members’ interest in this matter to sell a lawful ingredient. FDA’s warning letters on NAC are not final agency actions, but rather should be viewed as the opening salvo, inviting those with sound legal arguments to respond, which we are doing.”

—Steve Mister, CRN President & CEO, Natural Products Insider, December 2020

JUNE 2021 UPDATE: CRN petition requests FDA reverse position on NAC


As previously reported to our members, several companies are learning that Amazon is removing NAC-containing products from its retail platform.

Here's what CRN has done to address the matter thus far: 



FDA position on NAC 'invalid on multiple legal grounds,' CRN says

CRN declared “legally invalid” FDA’s new policy prohibiting manufacturers from marketing products containing NAC as dietary supplements under the Federal Food, Drug, and Cosmetic Act (FDCA).

In a letter to FDA Director of Dietary Supplement Programs Steven Tave, CRN called the change, as seen in July 2020 via warning letters, “a sudden and drastic departure from past agency practice" and urged the agency to revert to its longstanding policy of permitting supplement products containing NAC. 

It is unclear whether FDCA section 201(ff)(3)(B)(i) applies to NAC, as FDA records of NAC’s drug approval contain unreliable and conflicting information, CRN noted. Additionally, as cited in Nutritional Outlook's coverage of CRN's action, "NAC drugs approved prior to 2016 appear to be comprised of different forms of NAC compared to those found in dietary supplements."

CRN called the policy change "an arbitrary and capricious agency action that is invalid under the Administrative Procedure Act," noting that FDA's new position is not only unenforceable but also violates the "well-established presumption against statutory retroactivity." Read more.


Member Alert and Member Feedback Requested: FDA Targets Sale of NAC Dietary Supplements 

Last week FDA sent seven warning letters to companies for allegedly making illegal disease claims that their products could cure, treat, mitigate, or prevent hangovers. CRN is requesting member feedback. CRN members read more.