Phenibut

Phenibut (β-phenyl-GABA, β-phenyl-γ-aminobutyric acid) — a Soviet-developed GABA-B receptor agonist prescribed as an anxiolytic/nootropic in Russia (Anvifen/Fenibut/Noofen), with NO Western regulatory approval and a serious dependence/withdrawal liability

A GABA-B receptor agonist — β-phenyl-GABA — developed in the USSR and still prescribed there as an anxiolytic and nootropic (brands Anvifen, Fenibut, Noofen). It is NOT approved in the US, UK or EU, where it is sold online as a 'nootropic' or anxiolytic 'supplement' and used recreationally for anxiety, sleep and sociability. A genuine but mostly Russian, limited clinical literature supports its anxiolytic use; the DOMINANT Western literature, however, is case reports of DEPENDENCE, rapid TOLERANCE, and severe WITHDRAWAL — agitation, insomnia, psychosis, delirium and seizures resembling baclofen or alcohol/benzodiazepine withdrawal — plus OVERDOSE/toxicity with reduced consciousness requiring intensive care. Phenibut is dangerous combined with alcohol or other CNS depressants. Frame: a real GABA-B anxiolytic carrying a serious dependence and withdrawal risk and almost no Western regulatory standing. Informational, harm-reduction entry only — not a recommendation.

The commonly studied dose of Phenibut is There is no Western-approved or endorsed human dose. Phenibut is an unapproved GABA-B agonist with a serious dependence and withdrawal liability; this library does NOT provide a recommended dosing protocol. For context only, where it is prescribed abroad (Russia, as Anvifen/Fenibut/Noofen) typical anxiolytic doses are in the order of 250–500 mg up to a few times daily for short courses, and the pharmacology literature describes that range — but recreational/grey-market use commonly involves higher and escalating doses, and any regular use risks tolerance, dependence and a dangerous withdrawal syndrome. The safest dose is none; if it has been used regularly, do NOT stop abruptly — taper under medical supervision.. Individual needs vary — start at the lower end of the range and adjust based on how you respond.

An atypical antidepressant — brand Stablon/Coaxil/Tatinol — approved and prescribed for major depression (and anxious depression) in parts of Europe, Asia and Latin America, where randomized trials show efficacy comparable to SSRIs and tricyclics, often with better tolerability at the therapeutic dose (12.5 mg three times daily). Mechanistically it is unusual: it modulates the stress system and enhances glutamatergic/hippocampal plasticity, and — the critical fact for harm reduction — it is a FULL MU-OPIOID RECEPTOR AGONIST. That opioid action explains both its antidepressant effect AND its abuse potential. In the United States it is NOT FDA-approved; the FDA has warned about it, and it is sold illicitly as an unapproved 'nootropic'/'supplement' ('Tianaa', 'Za Za', 'Pegasus') nicknamed 'gas station heroin'. The dominant recent US literature is not efficacy but ABUSE, DEPENDENCE, opioid-like WITHDRAWAL, overdose/toxicity (usually at supratherapeutic doses far above the clinical dose), and rising poison-center exposures. The honest framing: a genuine antidepressant abroad with proven short-term efficacy at the prescribed dose, but a mu-opioid agonist carrying real dependence/abuse/withdrawal/overdose risk and no US approval. Informational, harm-reduction entry only — not a recommendation, and not a substitute for clinician-supervised treatment.

This GABA-B/α2δ profile is the basis of both its calming, sleep-promoting and pro-social subjective effects and its dependence and withdrawal liability. Phenibut has NEVER been approved as a medicine in the United States, United Kingdom or European Union.

In the West it occupies a grey market: it is sold online as a 'nootropic' or anxiolytic dietary 'supplement' and is widely used recreationally for anxiety relief, sleep, and increased sociability. The honest reading of its evidence base is split.

On one side there is a genuine but mostly Russian, older and methodologically limited clinical literature describing anxiolytic and nootropic use, summarised in the widely cited pharmacology review by Lapin (2001), which characterises phenibut as a tranquiliser and nootropic acting via GABA-B.

On the other side — and dominating the modern, peer-reviewed Western literature — is a steady stream of case reports and case series documenting harm: physiological DEPENDENCE that develops with regular use, rapid TOLERANCE that drives dose escalation, and a severe WITHDRAWAL syndrome on abrupt cessation.

Reported withdrawal features include rebound anxiety and insomnia, agitation, tremor, autonomic instability, hallucinations and frank PSYCHOSIS, delirium, and SEIZURES — a picture clinicians repeatedly liken to baclofen withdrawal and to alcohol/benzodiazepine withdrawal, and which has required management with benzodiazepines, baclofen substitution or phenobarbital tapers (Ahuja 2018; Brunner 2017; Sethi 2021).

Acute OVERDOSE produces dose-dependent CNS depression — somnolence, reduced consciousness, sometimes agitation or delirium — and toxicity reports describe patients requiring intensive supportive care (Sankary 2017); a survey of availability and use characterised the desired effects alongside the acute toxicity profile and the ease of online purchase (Owen 2016).

The combination with alcohol or other CNS depressants is particularly dangerous because the sedative effects are additive.

The score reflects this reality squarely: phenibut is a real GABA-B anxiolytic with a plausible mechanism and some (largely non-Western, limited) efficacy literature, but it has no Western regulatory approval, no robust modern randomised evidence in the populations that actually use it, and a dominant peer-reviewed literature consisting of dependence, tolerance, severe withdrawal and overdose case reports.

It is sold and used as a supplement but is better understood as an unapproved GABAergic drug with a meaningful addiction and withdrawal risk. This is an informational, harm-reduction entry — not a recommendation, and not an endorsement of any dose or protocol.