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:
- 4-Amino-3-phenylbutanoic acid
- β-(aminomethyl)benzenepropanoic acid
- beta-(Aminomethyl)hydrocinnamic acid
- β-phenyl-γ-aminobutyric acid
FDA Issued Warning Letters:
- Atomixx (April 2019)
- Evol Nutrition Associates, Inc. (April 2019)
- NeusoScience (April 2019)
For More Information:
- Constituent Update (April 2019)
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.