Consumers cite health benefits of NAC in FDA comments

Many consumers have asked FDA to keep NAC (N-acetyl-L-cysteine) on the market in the U.S. as a dietary supplement, citing its health benefits including the ability to help with breathing problems.

The comments were submitted to FDA, in response to its request for information by Jan. 25 on the past use of NAC. FDA is reviewing two citizen petitions requesting the agency reconsider its position that NAC cannot be lawfully marketed in a dietary supplement since it was first approved as a drug in 1963.

NAC helps the body replenish its stores of glutathione, an antioxidant, and features several other health benefits, according to WebMD. A 2019 article in the journal Antioxidants described NAC as “a precursor to the amino acid L-cysteine and consequently the antioxidant glutathione” that is commonly found in onion.

Eugene Samson was among a handful of consumers requesting FDA allow NAC to continue to be available as a dietary supplement.

“The use of NAC has helped those with various lung conditions to improve their breathing,” he wrote in comments available on a regulatory docket that FDA opened in connection with the two citizen petitions filed by the Council for Responsible Nutrition (CRN) and Natural Products Association (NPA). “I have personally witnessed this with those I know and advocate for the continued use of NAC in this way.”

Calvin Henry told FDA he has suffered from the harmful effects of a lung disease for many years, and medical professionals advised him to use NAC.

“I have used NAC as a dietary supplement since 2007 and continue to do so for ongoing lung/health maintenance and general health and well-being with benefit and zero ill effects,” Henry wrote.

Stephanie Cevelin said she suffers from allergies, asthma and post-nasal drip, and she learned about NAC after contracting COVID-19.

“NAC helped my sinuses clear and the inflammation seemed a lot less, not only in my sinuses, but in my breathing,” Cevelin wrote. “I haven’t had to use my inhaler as often.”

Gerald Laprade said he has been using NAC for nearly a decade, “and it has helped my memory tremendously as well as improved my immune system.”

He questioned why FDA would target NAC during the pandemic “when we need to boost our immune system to avoid the virus.”

Another consumer said NAC has helped reduce her daughter’s “skin picking,” and she asked FDA to refrain from banning NAC, “or if you must take control, please make it available by prescription immediately.”

NAC is only available in the U.S. market as a dietary supplement, not as a prescription medicine.

“The product has been on the market [as a dietary supplement] since at least 1991,” said John Troup, chief science officer of Blueroot Health, the brand owner of Vital Nutrients, which sells NAC finished products.

He added in an interview, “There is no pharmaceutical company that we’ve been able to identity that’s even remotely interested in pursuing this [and] protecting it as a … prescription drug.”

FDA’s request for comments on the past use of NAC (in a Nov. 24 constituent update) could foreshadow a first-of-its-kind rulemaking to make an ingredient lawful in dietary supplements when a substance or “article” was first approved or studied as a drug. FDA has never exercised such authority since passage of the Dietary Supplement Health and Education Act of 1994 (DSHEA).

“If applicable, the FDA will use the information submitted to the public docket and other applicable information to determine if rulemaking to make NAC lawful as a dietary supplement is appropriate,” the agency disclosed in its constituent update.