Peptides›Cognitive›Phenibut

Phenibut

/ GABA-B receptor agonist (small molecule, β-aryl-GABA derivative)

TIER 2 · TranslationalN = 0 · TESTING PENDINGMW 179.22 g·mol⁻¹

ALIAS · β-Phenyl-GABA · Anvifen (trade — Russia) · Noofen (trade)

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Research use onlyAny dose figures below describe what specific cited studies used, reported factually. Nothing on this page is guidance for human use.READ FIRST →

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§ A · Identity

Primary sequence— sequence not captured —

MW · 179.22CLASS · GABA-B receptor agonist (small molecule, β-aryl-GABA derivative)CATEGORY · Cognitive

Tier 2. Approved as an anxiolytic / nootropic in Russia and Belarus since the 1960s; substantial Russian-language clinical literature on therapeutic use. In Western literature the principal indexed material concerns acute toxicity, dependence, and withdrawal case reports rather than efficacy trials. The FDA has issued warnings against marketing phenibut as a dietary supplement.

§ B · Mechanism of action

Phenibut is a β-phenyl-substituted analog of γ-aminobutyric acid (GABA) with primary agonist activity at the GABA-B receptor and weaker activity at GABA-A. The phenyl substitution enables blood-brain barrier penetration that native GABA lacks. Activity at α-2-δ calcium-channel subunits has been proposed by analogy to gabapentin and baclofen but is not as well characterised pharmacologically.

§ C · Human clinical evidence

Tier 2. Russian clinical literature dating to the 1960s describes use as an anxiolytic, sleep aid, and nootropic adjunct. Western literature emphasises adverse-event reporting: case reports and case series of acute toxicity, withdrawal syndromes resembling alcohol or benzodiazepine withdrawal (autonomic instability, agitation, hallucinations, seizures), and dependence patterns developing over weeks to months of recreational use.

§ D · Primary literature

PubMed11830761Lapin I et al. — Phenibut (beta-phenyl-GABA): a tranquilizer and nootropic drug · CNS Drug Reviews · reviewNarrative review of phenibut pharmacology, Russian clinical history, and reported anxiolytic / nootropic effects; widely cited as the English-language entry point to the compound.Limitations: Narrative review by a Russian-tradition author; predates the Western dependence-case-report literature.2001

PubMed26693960Owen DR et al. — Phenibut (4-amino-3-phenyl-butyric acid): Availability, prevalence of use, desired effects and acute toxicity · Drug and Alcohol Review · human-observationalSurveyed online availability and self-reported use of phenibut, and characterised acute-toxicity presentations including agitation, reduced consciousness, and withdrawal patterns.Limitations: Survey and case-series methodology; self-report data; not a controlled exposure study.2016

§ F · Safety signal

The dependence and withdrawal signal is the dominant Western safety concern. Owen 2016 surveyed availability and prevalence of recreational use and documented acute toxicity presentations. Subsequent case-report literature has consistently described severe withdrawal in subjects who had escalated daily doses over weeks of unsupervised use. Co-ingestion with alcohol or benzodiazepines amplifies sedation and respiratory depression risk.

§ H · Regulatory status

Regulatory status

FDA status:: Not FDA-approved

§ I · Notable gaps and controversies

The mismatch between Russian therapeutic-use literature (which presents phenibut as a tolerable anxiolytic at controlled doses) and Western adverse-event literature (which presents it as a dependence-prone agent with severe withdrawal) is partly an artefact of the populations studied — supervised clinical use vs unsupervised recreational supplementation — and partly a methodological mismatch. The supplement-loophole channel through which phenibut is sold in the US bypasses the dose, duration, and supervision conditions assumed by the Russian therapeutic literature.