NAC, short for N-acetylcysteine, is a dietary supplement that has been around for decades. People use it for various reasons, including enhancing athletic performance and treating chronic lung conditions. In 2004, the U.S. Food and Drug Administration (FDA) approved NAC to treat life-threatening liver side effects of acetaminophen overdose. In the fight against COVID-19, the supplement has been shown to have excellent potential as an effective treatment. With that in mind, though not the final word, the FDA recently reversed its longstanding position on NAC, postulating that it is a “medication,” therefore, it can not legally be marketed as a dietary supplement and should be removed from public sale.

For many years, NAC, which is turned into glutathione by the body when consumed, has been widely used as a standalone product in whole dietary supplements. The FDA’s Office of Dietary Supplement Program (ODSP), maintained by the National Institutes of Health (NIH), currently shows almost 1,500 products containing NAC. 

Currently, NAC is being studied as a treatment for COVID-19 in several actively recruiting clinical trials across the country. With the FDA alleging it first approved NAC as a drug on Sept. 14, 1963, the FDA is again going after NAC, claiming it does not qualify as a legal dietary supplement. The agency sent warning letters in July 2020 to seven companies selling products containing NAC, arguing that NAC couldn’t legally be sold in a dietary supplement because the ingredient was first approved as a drug (in 1963). Back in September, Dr. Anthony Fauci, skeptical about recommending any supplements for treating COVID-19, admitted he took supplemental vitamin D and C, adding, but “any of the other concoctions and herbs I would not do.”

In reaction to the FDA’s warning letters, the Council for Responsible Nutrition (CRN) sent a detailed letter to the FDA on Dec. 4, 2020, pleading with the Agency to reverse its invoked Drug Exclusion Provision in U.S. code Title 21 to ban the sale of NAC, thus prohibiting manufacturers from marketing products containing NAC as dietary supplements. Noting that thousands of consumers have come to rely on these products as a vital source of nutrients, the letter also calls into question information the CRN obtained through the FOIA, showing what appears to be a handwritten approval date of “1963,” raising several questions about the reliability of the approval date. The letter asserts:

This policy—which represents a sudden and drastic departure from past Agency practice—is legally invalid. As such, FDA should revert to its longstanding policy of allowing manufacturers to market products containing NAC as dietary supplements.

For decades, manufacturers have safely marketed products containing NAC as dietary supplements in the United States. There are currently hundreds of dietary supplements containing NAC on the market, and thousands of consumers have come to rely on these products as a crucial source of nutrients. And, until recently, FDA has consistently and affirmatively permitted manufacturers to market these products. In fact, FDA has considered over 100 structure-function claim notifications regarding NAC and at least one qualified health claim petition for a dietary supplement containing NAC and has not objected to the presence of NAC in any of these products.

Last month, according to several industry sources, Amazon began removing dietary supplement products from its platform that contain NAC (which has a long list of therapeutic uses), and a quick search seems to show that very few if any products remain today. Neil Levin, senior nutrition education manager for NOW, a leading dietary supplement company, recently spoke about NAC in an email:

“NAC is one of the supplements that have dual-use as drug and supplement, as do fish oil, niacin, potassium, etc., that also have prescription forms. Just as not all niacin or fish oil products are sold by prescription, not all NAC is, either. And we don’t make drug claims that would warrant calling our products’ drugs.'”

The National Institutes of Health (NIH) published a study in January 2011 examining NAC’s role in treating addictive behavior. The study concluding that multi-purpose medical and dietary NAC—the supplemental form of L-cysteine, which is a semi-essential amino acid present in our bodies—plays a prominent metabolic role in the body’s overall antioxidant activities by controlling the glutamatergic system (i.e., the regulation of reward, reinforcement, and relapse). The research found NAC quite promising, concluding, “At present, NAC appears to be a compound worth watching—one that may, in the future, play a valuable role in both psychiatric and medical settings.” Labeling NAC as a “safely used supplement,” the decades-old study indicated:

In addition to prescription availability, NAC is commercially accessible as an over-the-counter product and has been safely used as a supplement in humans for years (NAC is relatively rare in food). Commercial NAC is available in 500-mg tablets and capsules, 600-mg tablets and capsules, 750-mg capsules, and 1000-mg tablets.

An article out today by PRN, titled “The FDA, Shock Troops for the Pharmaceutical Industrial Complex,” calls into question the notion that individuals who have been fully vaccinated against COVID-19 are protected and touches on the multiple instances where the FDA has attempted to ban effective natural supplements, including curcumin, boswellia and aloe vera from pharmacologic compounding, and now they are striving to do the same to NAC.

While it is unclear if other offices or agencies within the FDA are involved in the evaluation process surrounding NAC (which has been researched by Dr. Fauci as a treatment for HIV) and its potential complete removal as a dietary supplement, on May 10, Cara Welch, Ph.D., Acting Director of the FDA’s ODSP, replied to CRN’s letter stating the Agency is “closely reviewing the information provided in your letter and will provide a more substantive response once our evaluation is complete.”