Phenibut Exposures Reported to U.S. Poison Centers, 2009–2019: A Rising, Unregulated Drug

Phenibut (β-phenyl-γ-aminobutyric acid) is an unregulated drug developed in Russia in the 1960s as an antianxiety medicine said to enhance thinking. Online sellers have built a growing U.S. market for it, advertising it for anxiety, relaxation and sleep. Using or misusing it can cause sedation, slowed breathing and reduced consciousness, and withdrawal can bring anxiety, agitation and acute psychosis.

In the U.S., phenibut is legal to possess but not an FDA-approved drug. It's sold online as a supplement, but the FDA has ruled it doesn't qualify as a dietary ingredient and can't be listed in dietary supplements. It isn't detected on routine urine drug screens.

What poison centers saw

From January 2009 to December 2019, U.S. poison centers took calls on 1,320 phenibut exposures from all 50 states and DC.

Phenibut exposure cases by year, National Poison Data System, 2009–2019. CDC

Cases rose sharply, especially from 2015, when poison centers could first record exposures under the name "phenibut."

Unintentional exposures were more common in people under 18 (21.9%) — and made up 93.3% of exposures in children under 10, against 6.3% in adults.

Effects

49.6% had moderate effects (no long-term harm). One in eight (12.6%) had major effects — life-threatening, or causing significant disability or disfigurement — and three people died. Even when phenibut was the only substance involved, 10.2% had major effects, including one death.

What it means

Why exposures rose isn't known, but phenibut's growing popularity and easy online availability may play a part, along with its potential for dependence. Clinicians and the public need to know about phenibut as an emerging drug of use and misuse, and education about its dangers could help prevent harm, including death.

Poison center data are reported voluntarily and can't all be verified, so they may not capture every exposure, and phenibut exposures aren't confirmed by lab tests.

Sources

Based on Graves JM, Dilley J, Kubsad S, Liebelt E, "Notes from the Field: Phenibut Exposures Reported to Poison Centers — United States, 2009–2019," MMWR volume 69, number 35, Centers for Disease Control and Prevention; a work of the United States government in the public domain. Data from the American Association of Poison Control Centers' National Poison Data System.