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Phenibut: Wikis


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Systematic (IUPAC) name
4-amino-3-phenyl-butanoic acid
CAS number 1078-21-3
ATC code none
PubChem 14113
Chemical data
Formula C 10H13NO2  
Mol. mass 179.216 g/mol
SMILES eMolecules & PubChem
Synonyms Fenibut, Phenybut, PhGABA
Physical data
Melt. point 253 °C (487 °F)
Pharmacokinetic data
Bioavailability  ?
Metabolism  ?
Half life 5 hours
Excretion  ?
Therapeutic considerations
Pregnancy cat.  ?
Legal status OTC (US)
Routes Oral

Beta-phenyl-gamma-aminobutyric acid, better known as Phenibut or less commonly Fenibut or Phenybut, is natural derivative of the inhibitory neurotransmitter GABA (Gamma amino butyric acid). Sold as a dietary supplement in the US while in Russia sold as a neuropsychotropic drug that is capable of passing the blood-brain barrier. Phenibut is cited as a nootropic for its ability to improve neurological functions. It was discovered in Russia in the 1960s, and has since been used there to treat a wide range of ailments including anxiety and insomnia.

The name Phenibut, along with many of the other names for the compound, comes directly from the chemical name for the compound, beta-phenyl-gamma-aminobutyric acid.


Contraindications and side effects

Phenibut can have unpleasant dose-dependent withdrawal symptoms. Withdrawal symptoms can include acute anxiety and insomnia that can last for up to two weeks afterwards. Withdrawal symptoms, however, are almost always associated with cessation after prolonged usage.

Phenibut is not to be mixed with alcohol, sedatives or prescription medication without consulting with a healthcare professional.

Persons on MAO inhibitors or epilepsy medications like carbamazepine or oxcarbazepine should consult with their physician or pharmacist prior to supplementation with phenibut. Clinical research has demonstrated that phenibut can potentiate or inhibit the function of some epilepsy medications.


Commonly recommended doses are 250-3,000 mg as needed or daily with weekly cycling off during weekends.


Structurally, phenibut is gamma-aminobutyric acid with a phenyl group in the beta position. It has structural similarities to baclofen and phenethylamine. Phenibut is a GABAB receptor agonist, with slight activity at GABAA receptors. It also is a beta-phenylethylamine antagonist and thus reduces the effects of phenylethylamine and other compounds that raise phenlethylamine levels  .

Furthermore, it has shown to stimulate dopamine receptors. The pharmacological effects of phenibut are similar to baclofen, but less potent per milligram of dosage.


  • Shulgina GI (1986). "On neurotransmitter mechanisms of reinforcement and internal inhibition". Pavlov J Biol Sci 21 (4): 129–40. PMID 2431377.  
  • Chojnacka-Wójcik E, Hano J, Sieroslawska J, Sypniewska M (1975). "Pharmacological properties of gamma-animobutyric acid and it derivatives. IV. Aryl gaba derivatives and their respective lactams". Arch. Immunol. Ther. Exp. (Warsz.) 23 (6): 733–46. PMID 1241266.  
  • Lapin I (2001). "Phenibut (beta-phenyl-GABA): a tranquilizer and nootropic drug". CNS Drug Rev 7 (4): 471–81. PMID 11830761.  
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  • Talalaenko AN, Pankrat'ev DV, Goncharenko NV (2002). "[Monoaminergic and aminoacidergic mechanisms of the posterior hypothalamus in realization of the antiaversive effects of anxiosedative and anxioselective agents in various anxiety models]" (in Russian). Eksp Klin Farmakol 65 (5): 22–6. PMID 12596508.  
  • Talalaenko AN, Pankrat'ev DV, Goncharenko NV (September 2001). "[Neurochemical characteristics of the ventromedial hypothalamus and anti-aversive effects of anxiolytic agents in various anxiety models]" (in Russian). Ross Fiziol Zh Im I M Sechenova 87 (9): 1217–26. PMID 11763535.  
  • Kresiun VI (1984). "[Mg2+-ATPase activity of brain mitochondria fractions in chronic stress and its correction by psychotropic agents]" (in Russian). Ukr. Biokhim. Zh. 56 (6): 637–41. PMID 6151270.  
  • Karkishchenko NN, Dimitriadi NA (1991). "[The adequacy of a new method for assessing the vestibular protective effect of biologically active substances]" (in Russian). Farmakol Toksikol 54 (5): 14–6. PMID 1800137.  

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