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  5. Phenibut in Dietary Supplements
  1. Information on Select Dietary Supplement Ingredients and Other Substances

Phenibut in Dietary Supplements

Phenibut is a substance that does not meet the statutory definition of a dietary ingredient.

The Federal Food, Drug, and Cosmetic Act (FD&C Act) defines a dietary ingredient as a vitamin; mineral; herb or other botanical; amino acid; dietary substance for use by man to supplement the diet by increasing the total dietary intake; or a concentrate, metabolite, constituent, extract, or combination of the preceding substances. Because phenibut does not fit any of the categories of dietary ingredients under the FD&C Act, any dietary supplements that declare phenibut as a dietary ingredient are misbranded.

Phenibut is also known as:

  • fenibut
  • phenigam
  • PGaba
  • PhGaba
  • Phenibut HCl
  • Phenigamma
  • Phenygam
  • Phenylgam
  • Phenyl-GABA
  • 4-Amino-3-phenylbutanoic acid
  • β-(aminomethyl)benzenepropanoic acid
  • beta-(Aminomethyl)hydrocinnamic acid
  • β-phenyl-γ-aminobutyric acid

On June 2, 2023, U.S. District Court Judge Margaret R. Guzman (D. Mass.) entered an order of permanent injunction against Daniel R. Marold, an individual doing business as “Chill6,” for distributing unapproved and misbranded drug products and adulterated food. The products distributed by Chill6 allegedly contain, among other things, Phenibut HCl, which does not meet the statutory definition of a dietary ingredient and is an unsafe food additive. The products distributed by Chill6, various flavors of “Chill6” beverage powder, also included labeling that claims the product is intended to cure, mitigate, treat, and/or prevent at least four diseases: insomnia, alcoholism, posttraumatic stress disorder (PTSD), and anxiety disorder.

FDA Issued Warning Letters:

For More Information:

This webpage describes FDA’s views and recent actions with regard to an ingredient used in products marketed as dietary supplements.  If you have evidence that calls FDA’s views into question, we invite you to submit it, along with your reasoning, to FDA at ODSP@fda.hhs.gov.

This page is not intended to provide a complete list of all FDA actions and communications with regard to this ingredient and its use in products marketed as dietary supplements.

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