The FDA has recently adopted a position that federal law, the Federal Food, Drug, and Cosmetic Act (FDCA), prohibits manufacturers from marketing products containing N-acetyl-L-cysteine (NAC) as dietary supplements.
In July 2020, the FDA sent warning letters to multiple companies who marketed products, some of which included NAC, that claimed to cure hangovers. In the letters, the FDA stated that the marketed dietary supplements were unapproved new drugs that have yet to be evaluated for safety or effectiveness. The FDA claims that NAC cannot be lawfully marketed as a dietary supplement because the ingredient was approved as a drug in 1963. CRN and many other industry groups have questioned the legality and reliability of the 1963 date since it appears to be on a handwritten letter of approval.
Additionally, the 1963 approval date was for an inhaled drug, not orally ingested, which CRN says goes against FDA's own precedent of approving drugs differently based on the route of administration and dosage form.
The FDA's sudden challenge of the status of NAC as a dietary supplement is an unexpected pivot given an absence of safety concerns related to the ingredient.
So why is the FDA targeting an ingredient that is safe, commonly used, and has a long history of the agency permitting manufacturers to market it as a dietary supplement? The answer is unclear. It is clear, however, that restricting patient access to critical medications will negatively affect the health of patients.
It is important to note that the FDA hasn’t taken final agency action on NAC, meaning their current position is not final and discussions with industry groups and FDA are still ongoing. That is why it is important for manufacturers, healthcare providers, and patients to be informed and ready to use their voice when the time comes.