Debate on NAC’s legal status in supplements rages on as industry slams FDA delays

25 Nov 2021 --- The US nutrition industry hit back at the Food and Drug Administration (FDA) over the legal issues surrounding the use of antioxidant N-acetyl-L-cysteine (NAC) in products marketed as dietary supplements.

As part of ongoing debate on the legal use of NAC in supplements, the FDA has asked for additional information to review, before considering changing the rules and stating NAC can be legally used in supplements. 

Industry however considers the issue moot, citing the Dietary Supplement Health and Education Act (DSHEA) and slamming the FDA for not resolving the issue faster. 

“FDA’s delay is a disservice to the dietary supplement industry, retailers, health care practitioners, and most importantly, the more than 200 million supplement users who rely on FDA to do its job,” says Steve Mister, president and CEO of trade association the Council for Responsible Nutrition (CRN).

Ongoing battle
NAC is approved as a drug, though its position in supplements is a heated debate.The issue came to the fore last year when the FDA sent warning letters to seven companies for claiming their products could address hangovers.

“Dietary supplements that claim to cure, treat, mitigate, or prevent hangovers could potentially harm consumers, particularly young adults, who may be led to believe that using these products, rather than drinking in moderation or not at all, can prevent or mitigate health problems caused by consuming too much alcohol,” said the FDA at the time.

The main debate surrounds the use of NAC, with the FDA stating its use is excluded from the dietary supplement definition. 

“NAC was approved as a new drug under section 505 of the Act [21 USC § 355] on September 14, 1963. The FDA is not aware of any evidence that NAC was marketed as a dietary supplement or as a food prior to that date,” one of the warnings highlights.

Industry reacts with petitions
FDA’s stance was hit back with two citizen petitions. In June this year, the CRN asked the FDA to reverse the agency’s position that NAC-containing products cannot be dietary supplements.

In August 2021, the Natural Products Association asked the FDA to either determine that NAC is not excluded from the definition of a dietary supplement or, alternatively, initiate rulemaking to make NAC a lawful dietary supplement under the Federal Food, Drug and Cosmetic Act. 

Now, the FDA has issued a tentative response to the petitions “requesting additional information from the petitioners and interested parties and noting that the agency needs additional time to carefully and thoroughly review the complex questions posed in these petitions.”

“The FDA is interested in receiving data and information on the earliest date that NAC was marketed as a dietary supplement or as a food, the safe use of NAC in products marketed as a dietary supplement, and any safety concerns,” states the FDA.

The information will be used to determine if “rulemaking to make NAC lawful as a dietary supplement is appropriate.”

Disappointment over FDA
The CRN describes the FDA’s response as “extremely dissatisfying” and disappointing. In a statement, Mister argues DSHEA’s provisions “may not be interpreted retroactively to remove ingredients that were lawfully marketed in 1994 and have enjoyed a long history of safe use since then.”

“The delay in clearing up the status of NAC by asking for more data and refusing to admit its error disregards the law and disserves consumers who use NAC.”

“As FDA unduly prolongs making clear NAC’s status, many retailers have discontinued selling supplements containing NAC in misplaced reliance on those warning letters, which means consumers have a difficult time locating these products,” highlights Mister.The FDA is accepting comments until January 25, 2022. 

NAC exclusive to pharma?
Mister argues that it should not be complicated for the FDA to determine the legality of NAC in supplements. “DSHEA makes clear that ingredients in use as dietary supplement ingredients prior to its enactment are grandfathered into the supplement marketplace.”

“Thus, pharmaceutical manufacturers could not have had any expectation of exclusivity in the years prior to the creation of this provision of the law. Given the long history of safe use of NAC, FDA cannot now try to establish a safety concern in order to award this ingredient exclusively to drug makers.”

The matter was also picked up by US Congressman Jeff Duncan, who last month sent a letter to the FDA requesting clarity. 

In September, the FDA was urged to crack down on illegal phenibut in supplements.

While the nutraceutical industry has experienced growth, particularly in light of the COVID-19 pandemic, the dietary supplement industry is also seen to be facing consumer mistrust. 

Edited by Andria Kades