Other anxiolytics (local classification)
ATC code: N05BX-PHENIBUT (Phenibut (local code))
A GABA analogue with a phenyl ring. The primary mechanism is agonism at the GABA-B receptor, with activity at the GABA-A receptor and voltage-gated calcium channels at higher doses. Synthesised in the USSR in the 1960s for Soviet cosmonauts. Not registered as a medicine internationally but sold in CIS countries. FDA and European regulators increasingly report dependence and overdose cases among 'nootropic' supplement users who acquire phenibut via online grey markets.
Not recommended
International alcohol withdrawal guidelines (ASAM 2020, WFSBP) list benzodiazepines as first-line therapy. Phenibut is proposed in some Russian addiction protocols but lacks methodologically strong RCTs outside Russia.
Not recommended
Phenibut is not included in international GAD guidelines (APA 2023, NICE CG113). First-line therapy is SSRIs, SNRIs, and CBT. Phenibut has pharmacological kinship with baclofen, and small Soviet-era Russian RCTs suggest an anxiolytic effect, but the methodological quality does not meet modern standards. A separate concern is the growing number of dependence cases and severe withdrawal syndromes.
Not recommended
In biohacker communities and forums phenibut is promoted as a 'nootropic' for studying, work, public speaking, and dating. International publications and FDA/TGA warnings from 2019-2022 describe rising dependence and overdose cases specifically among users of 'nootropic' supplements containing phenibut purchased online. Cognitive improvements in healthy adults are not demonstrated in RCTs.
Not recommended
Phenibut is sometimes prescribed in Russian practice for insomnia due to its GABAergic effect. International insomnia guidelines (AASM 2021, NICE CG193) do not include it. Chronic phenibut use for insomnia is particularly dangerous – dependence and severe withdrawal develop, and withdrawal itself aggravates sleep disturbance.
Not recommended
For panic disorder, international guidelines (APA 2023) recommend SSRIs, SNRIs, and CBT. Phenibut has not been studied or recommended in this role.
Pregnancy safety data are limited; the drug is contraindicated.
Contraindicated during breastfeeding.
Phenibut is evaluated for the following indications with varying evidence strength: Generalized anxiety disorder (evidence tier D), Alcohol withdrawal syndrome (evidence tier D), Insomnia (evidence tier F). See the full indication matrix with dosing and citations above on this page.
Common side effects of Phenibut (≥ 1 in 100): Drowsiness, Nausea, Headache, Irritability, agitation. See the Safety section for uncommon and serious reactions.
Pregnancy safety data are limited; the drug is contraindicated.
Contraindicated during breastfeeding.
Phenibut is contraindicated in: Hypersensitivity to any component; Pregnancy and breastfeeding; Age under 3 years; Acute renal failure; Peptic ulcer of the stomach and duodenum. Full list in the Safety section.