For broader research context on nootropic compounds, including comparative stacks, cycling considerations, and interaction notes, see the Complete Nootropic Cheat Sheet.
What Is Phenibut?
Phenibut, also called beta-phenyl-GABA, is a synthetic analogue of gamma-aminobutyric acid (GABA). It was developed in the Soviet Union during the 1960s by modifying the GABA molecule with a phenyl ring. This structural change increases lipophilicity and allows a portion of the compound to cross the blood-brain barrier, unlike GABA itself, which has very limited penetration into the central nervous system. Phenibut has been described in Soviet and post-Soviet pharmacology literature as an anxiolytic and tranquilizing agent, and historical accounts state that it was included in medical supplies associated with Soviet cosmonaut programs because it was intended to reduce anxiety without necessarily causing the same degree of cognitive impairment as conventional sedatives.
Phenibut has been used as a prescription or regulated medicine in Russia and several Eastern European countries under names such as Noofen and Anvifen. It is not approved by the United States Food and Drug Administration as a medication or dietary supplement ingredient, and it is subject to regulatory restrictions and import controls in the United States. Its legal status differs across European jurisdictions, and the statement that it is generally unscheduled in the United States or European Union should not be interpreted as approval, safety, or uniform legality: national rules vary, products may be seized or refused entry, and commercial preparations can be mislabeled or contaminated. Online availability as a powder or capsule has contributed to nonmedical use, often under the nootropic label, despite limited high-quality clinical evidence and a substantial dependence liability.
Quick Reference
Member reference tables summarize the compound's research parameters.
Research Indications
Research Protocols
As reported in cited literature and research-community logs (see Research Citations below), not a personal dosing recommendation.
This member section describes parameters reported in the research literature.
Peptide Interactions
This member section summarizes reported compound interactions and evidence limitations.
Reported Research Time Points
This member section summarizes reported research time points.
Safety Notes
Included for harm-reduction awareness only, in the event this compound is encountered outside its labeled research use. Inclusion here does not imply RUO Codes endorses, recommends, or instructs human use.
This member section discusses research safety considerations and uncertainties.
Quality Indicators
Research Citations
- Phenibut (beta-phenyl-GABA): a tranquilizer and nootropic drug
Lapin, I., 2001, CNS Drug Reviews - Phenibut: A Novel Drug of Abuse and Potential for Overdose
Samokhvalov, A. V., et al., 2016, Journal of Medical Toxicology - Phenibut exposures and clinical effects reported to a regional poison center
McCabe, D. J., et al., 2018, Clinical Toxicology - Acute phenibut withdrawal: a comprehensive literature review and case report
Brunner, E., et al., 2018, CNS Drugs