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Why the FDA banned NAC (N-Acetyl Cysteine)

Updated: Jul 5, 2021

NAC (N-acetyl-L-cysteine) is a derivative of the amino acid L-cysteine and is a precursor of the cellular antioxidant glutathione. While L-Cysteine is readily found in the diet - and mostly from lean meat sources, NAC is not present in the diet and must be obtained via dietary supplementation. Recently, the FDA banned NAC for use in dietary supplements .

NAC was first approved by the FDA as a respiratory drug in 1963. It’s also used to prevent serious liver damage from acetaminophen poisoning and alcohol poisoning. Additionally, NAC has been available in dietary supplement products for decades – the ingredient itself is likely safe for most people; as in there are limited reports of adverse events.

The FDA has pushed back on the use of NAC in supplements since 2010, but it’s ramped up significantly this year. The FDA claims that there’s no evidence that NAC was used as a supplement prior to its use as a drug – so including NAC in a supplement makes the product an unapproved drug and thus illegal.

From a personal standpoint, I became aware of NAC way back when I was first dating my husband Kevin. As Kevin was a natural bodybuilder, he had been doing a lot of research on natural supplements that could be used to optimize health and body composition. Research has established that NAC exerts powerful antioxidant effects. Effectively, what NAC does is scan the body for, and neutralizes, harmful free radicals that can cause oxidative damage to muscle tissue, bodily organs, and DNA.

As an antioxidant, it may reduce oxidative stress, thereby preventing the onset of some cancers and possibly slowing the aging process. NAC may also boost immune system function by acting as a glutathione precursor. Glutathione is known as the most powerful antioxidant in the world. Glutathione is believed to protect other antioxidants (among them, vitamins C and E), prolonging and enhancing their effectiveness.

So imagine my surprise when I found out that the FDA banned NAC in the United States for supplementary use very recently, for what seems like a technicality rather than a safety issue. Ironically, the mechanism of action is to activate your body's innate ability to heal itself. A big reason why I recommend NAC is because it reduces inflammation in the body and it can actually play a big part in truly detoxifying the body. To all those who currently reside in Canada, NAC is still available ... for now.

CRN (The Council of Responsible Nutrition) challenged the FDA's decision to ban NAC a in a letter sent in December 2020, noting concerns about the reliability of decades-old NAC drug approval records; suggesting that FDA’s past conduct towards NAC bars this “sudden and drastic change in practice,” a reference to the fact that FDA has considered dozens of structure-function claims for NAC without objection; and questioning the legality of FDA’s interpretation of the drug preclusion provision of the FDCA as being retroactive.

The FDA has come back saying that they are reviewing the information in the letter and will advise once they have completed their evaluation. As of now, there is still no response and as such the case remains open.

Why do you think the FDA wants to ban NAC?


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