DEPARTMENT OF HEALTH AND HUMAN SERVICES
Food and Drug Administration
[Docket No. FDA-2022-D-0490]
Policy Regarding N-acetyl-L-cysteine: Draft Guidance for Industry; Availability
AGENCY: Food and Drug Administration, Health and Human Services (HHS).
ACTION: Notice of availability.
SUMMARY: The Food and Drug Administration (FDA or we) is announcing the availability of
a draft guidance for industry entitled “Policy Regarding N-acetyl-L-cysteine: Draft Guidance for
Industry.” The draft guidance, when finalized, will explain our intent to exercise enforcement
discretion with respect to the sale and distribution of certain products that contain N-acetyl-L-
cysteine (NAC) and are labeled as dietary supplements. This enforcement discretion policy
would apply to products that would be lawfully marketed dietary supplements if NAC were not
excluded from the definition of “dietary supplement” and that are not otherwise in violation of
the Federal Food, Drug, and Cosmetic Act (FD&C Act).
DATES: Submit either electronic or written comments on the draft guidance by [INSERT
DATE 30 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER] to ensure
that we consider your comment on the draft guidance before we begin work on the final version
of the guidance.
ADDRESSES: You may submit comments on any guidance at any time as follows:
Submit electronic comments in the following way:
Federal eRulemaking Portal: https://www.regulations.gov. Follow the instructions for
submitting comments. Comments submitted electronically, including attachments, to
https://www.regulations.gov will be posted to the docket unchanged. Because your
comment will be made public, you are solely responsible for ensuring that your comment
This document is scheduled to be published in the
Federal Register on 04/22/2022 and available online at
federalregister.gov/d/2022-08560, and on govinfo.govdoes not include any confidential information that you or a third party may not wish to be
posted, such as medical information, your or anyone else’s Social Security number, or
confidential business information, such as a manufacturing process. Please note that if
you include your name, contact information, or other information that identifies you in
the body of your comments, that information will be posted on
If you want to submit a comment with confidential information that you do not wish to be
made available to the public, submit the comment as a written/paper submission and in
the manner detailed (see “Written/Paper Submissions” and “Instructions”).
Submit written/paper submissions as follows:
Mail/Hand delivery/Courier (for written/paper submissions): Dockets Management Staff
(HFA-305), Food and Drug Administration, 5630 Fishers Lane, Rm. 1061, Rockville,
For written/paper comments submitted to the Dockets Management Staff, FDA will post
your comment, as well as any attachments, except for information submitted, marked and
identified, as confidential, if submitted as detailed in “Instructions.”
Instructions: All submissions received must include the Docket No. FDA-2022-D-
0490for “Policy Regarding N-acetyl-L-cysteine: Draft Guidance for Industry.” Received
comments will be placed in the docket and, except for those submitted as “Confidential
Submissions,” publicly viewable at https://www.regulations.gov or at the Dockets Management
Staff between 9 a.m. and 4 p.m., Monday through Friday, 240-402-7500.
Confidential Submissions–To submit a comment with confidential information that you
do not wish to be made publicly available, submit your comments only as a written/paper
submission. You should submit two copies total. One copy will include the information
you claim to be confidential with a heading or cover note that states “THIS DOCUMENTCONTAINS CONFIDENTIAL INFORMATION.” We will review this copy, including
the claimed confidential information, in our consideration of comments. The second
copy, which will have the claimed confidential information redacted/blacked out, will be
available for public viewing and posted on https://www.regulations.gov. Submit both
copies to the Dockets Management Staff. If you do not wish your name and contact
information to be made publicly available, you can provide this information on the cover
sheet and not in the body of your comments and you must identify this information as
“confidential.” Any information marked as “confidential” will not be disclosed except in
accordance with 21 CFR 10.20 and other applicable disclosure law. For more
information about FDA’s posting of comments to public dockets, see 80 FR 56469,
September 18, 2015, or access the information at:
Docket: For access to the docket to read background documents or the electronic and
written/paper comments received, go to https://www.regulations.gov and insert the docket
number, found in brackets in the heading of this document, into the “Search” box and follow the
prompts and/or go to the Dockets Management Staff, 5630 Fishers Lane, Rm. 1061, Rockville,
MD 20852, 240-402-7500.
You may submit comments on any guidance at any time (see 21 CFR 10.115(g)(5)).
Submit written requests for single copies of the draft guidance to the Office of Dietary
Supplement Programs, Center for Food Safety and Applied Nutrition, Food and Drug
Administration, 5001 Campus Dr., College Park, MD 20740. Send two self-addressed adhesive
labels to assist that office in processing your request. See the SUPPLEMENTARY
INFORMATION section for electronic access to the draft guidance.
FOR FURTHER INFORMATION CONTACT: Gerie Voss, Center for Food Safety and
Applied Nutrition (HFS-810), Food and Drug Administration, 5001 Campus Dr., College Park,
MD 20740, 240-620-9744; or Lauren Ferguson Baham, Center for Food Safety and AppliedNutrition, Office of Regulations and Policy (HFS-024), Food and Drug Administration, 5001
Campus Dr., College Park, MD 20740, 240-402-2378.
We are announcing the availability of a draft guidance for industry entitled “Policy
Regarding N-acetyl-L-cysteine: Draft Guidance for Industry.” We are issuing the draft guidance
consistent with our good guidance practices regulation (21 CFR 10.115). The draft guidance,
when finalized, will represent the current thinking of FDA on this topic. It does not establish any
rights for any person and is not binding on FDA or the public. You can use an alternate
approach if it satisfies the requirements of the applicable statutes and regulations.
FDA has determined that, under section 201(ff)(3)(B)(i) of the FD&C Act (21 U.S.C.
321(ff)(3)(B)(i)), NAC is excluded from the dietary supplement definition because NAC was
approved as a new drug before it was marketed as a dietary supplement or as a food. FDA
received two citizen petitions requesting that we conclude that NAC is not excluded from the
definition of dietary supplement under section 201(ff)(3)(B) of the FD&C Act. On March 31,
2022, we denied this request.
In addition, one of the citizen petitions asked FDA “to recommend and support to the
Secretary of HHS” that he issue a regulation that would determine NAC to be lawful under the
FD&C Act. As we stated in our response to the citizen petitions, we have not yet reached a final
decision on this request, but we are considering initiating rulemaking under section 201(ff)(3)(B)
of the FD&C Act to permit the use of NAC in or as a dietary supplement (i.e., to provide by
regulation that NAC is not excluded from the definition of dietary supplement), and, if, among
other considerations, FDA does not identify safety-related concerns as we continue our review of
the available data and information, we are likely to propose a rule providing that NAC is not
excluded from the definition of dietary supplement. While our full safety review of NAC
remains ongoing, our initial review has not revealed safety concerns with respect to the use ofthis ingredient in or as a dietary supplement. In addition, NAC-containing products represented
as dietary supplements have been sold in the United States for more than 30 years, and
consumers continue to seek access to such products.
Accordingly, the draft guidance, if finalized, would state our intent to exercise
enforcement discretion with respect to the sale and distribution of certain products that contain
NAC and are labeled as dietary supplements. The enforcement discretion policy would apply to
products that would be lawfully marketed dietary supplements if NAC were not excluded from
the definition of “dietary supplement” and that are not otherwise in violation of the FD&C Act.
Unless we identify safety-related concerns during our ongoing review, FDA would intend to
exercise enforcement discretion until either of the following occurs: we complete notice-and-
comment rulemaking to allow the use of NAC in or as a dietary supplement (if we move forward
with such proceedings), or we deny the citizen petition’s request for rulemaking. Should we
determine that this enforcement discretion policy is no longer appropriate, we will notify
stakeholders by withdrawing or revising this guidance in accordance with 21 CFR 10.115.
II. Paperwork Reduction Act of 1995
FDA tentatively concludes that this draft guidance contains no collection of information..
Therefore, clearance by the Office of Management and Budget under the Paperwork Reduction
Act of 1995 is not required.
III. Electronic Access
Persons with access to the internet may obtain the draft guidance at
guidance-documents, or https://www.regulations.gov. Use the FDA website listed in the
previous sentence to find the most current version of the guidance.
Dated: April 15, 2022.
Lauren K. Roth,
Associate Commissioner for Policy.[FR Doc. 2022-08560 Filed: 4/21/2022 8:45 am; Publication Date: 4/22/2022]
Special recognition to Michael Levine and the AANP for their work on this issue!