NAC is a derivative of the amino acid L-cysteine and a precursor of the cellular antioxidant glutathione. It is naturally occurring in foods like onions and garlic.
Despite being used as in supplements since the early 1990s, and therefore an “old dietary ingredient” according to the Dietary Supplement Health and Education Act of 1994 (DSHEA), the FDA declared in July 2020 that NAC was not a legal dietary ingredient because of its prior approval as a drug. NAC was first approved as an inhaled mucolytic drug in 1963.
The NAC issue concerned the industry as it saw the drug preclusion principle (which states an ingredient cannot be used in supplements if it is first approved as a drug) applied to an old dietary ingredient with decades of safe use. Many in the industry had assumed that such issues were settled for old dietary ingredients once DSHEA came into effect on Oct. 15, 1994.
In response to the FDA statements and market concerns, Citizen’s Petitions were filed in the summer of 2021 by the Natural Products Association (NPA) and the Council for Responsible Nutrition (CRN). The CRN petition asked the Agency to reverse its position that NAC-containing products cannot be dietary supplements. The NPA petition asked FDA to either determine that NAC is not excluded from the definition of a dietary supplement or, in the alternative, initiate rulemaking to make NAC a lawful dietary supplement under the Food, Drug, and Cosmetic Act.
At the end of March 2022, the Agency denied the CRN petition in its entirety and denied the first part of the NPA petition. In response to NPA’s request for rulemaking, FDA said it was considering this.
FDA published its final guidance in August, and stated it will exercise enforcement discretion for NAC, basically turning a blind eye to the sale of NAC-containing dietary supplement products so long as products are not making non-compliant disease claims. The guidance also initiates the process for export certificates for NAC.
While the Agency continues to explore the rulemaking process, one of the other unresolved issues – NPA’s lawsuit against FDA, which NPA filed at the end of 2021 – has now been dismissed by NPA.
“When the industry suffered significant economic harm as a direct result of the Agency’s long and inexplicable delays on a NAC regulatory path, NPA and its leadership led the way forward because of our commitment to the industry and holding FDA accountable,” said Daniel Fabricant, PhD, NPA President and CEO.
“We hope the agency uses this as a learning experience and handles other outstanding issues like CBD more appropriately.”
“This preserves our legal rights and demonstrates that we achieved our domestic objective through the enforcement discretion announcement, which is an unprecedented move for the agency. For exports, FDA has initiated a process and we continue to work directly with the agency and foreign governments to ensure exports on NAC return to levels prior to this series of events,” added Dr Fabricant.
“Thankfully, as a direct result of our lawsuit, the industry can sell domestically and internationally once again, maintain insurance, and ensure the FDA is consistent and meeting its basic regulatory obligations. As far as lawsuits go, while this was contentious at the start, as lawsuits can be, we were able to work cooperatively with the agency to bring NAC back via final guidance enforcement discretion.
“Legally, dismissing the case in this way enables us to preserve our standing, and refile this should FDA change their position on NAC in the future or take steps to inhibit commerce on NAC in the future.”