4-Amino-3-Phenylbutyric Acid, Acide 4-Amino-3-Phenylbutyrique, Acide Bêta-Phényl-Gamma-Aminobutyrique, Agente Gabaérgico, B-(Aminomethyl)Benzenepropanoic Acid, Beta-(Aminomethyl)Hydrocinnamic Acid, B-Phenyl-Gamma-Aminobutyric Acid, Beta-Phenyl-GABA, Bêta-Phényl-GABA, Beta-phenyl-gamma-aminobutyric acid, Fenibut, Phénibut, Phenigam, PhGaba, Phenigamma, Phenygam, Phenyl-GABA, Phényl-GABA.


Overview Information

Phenibut is a chemical similar to a brain chemical called gamma-aminobutyric acid (GABA). It is used as a recreational drug and as a medicine.

Phenibut is used for anxiety, insomnia, a type of anxiety that often develops after a terrifying event (post-traumatic stress disorder or PTSD), alcohol use disorder, and many other conditions. There is no good scientific evidence to support these uses. Also, using phenibut can be addictive.

How does it work?

Phenibut is similar to the brain chemical called gamma-aminobutyric acid (GABA). Research in humans shows that it might decrease anxiety and have other effects on the body.


Uses & Effectiveness?

Insufficient Evidence for

  • Alcohol use disorder.
  • Anxiety.
  • Depression.
  • Fatigue.
  • Fear.
  • Improving memory, learning, and thinking.
  • Insomnia.
  • Irregular heartbeat.
  • A type of anxiety that often develops after a terrifying event (post-traumatic stress disorder or PTSD).
  • Attention deficit-hyperactivity disorder (ADHD).
  • A disorder that causes leg discomfort and an irresistible urge to move the legs (restless legs syndrome or RLS).
  • Stress.
  • Tension.
  • Other conditions.
More evidence is needed to rate the effectiveness of phenibut for these uses.

Side Effects

Side Effects & Safety

When taken by mouth: Phenibut is POSSIBLY UNSAFE for most people. Phenibut can cause many side effects, including a hangover effect, dizziness, nausea, poor balance, fatigue, and feelings of electric shocks in the arms and legs. Phenibut in large doses can cause trouble breathing and unconsciousness.

Phenibut can cause dependence when taken regularly. People who use phenibut regularly and then stop taking it may experience withdrawal symptoms. These symptoms can include decreased appetite, nausea, muscle aches, anxiety, agitation, trouble sleeping, and seizures.

Special Precautions & Warnings:

Pregnancy and breast-feeding: There isn't enough reliable information to know if phenibut is safe to use when pregnant or breast-feeding. Stay on the safe side and avoid use.



We currently have no information for PHENIBUT Interactions.



The appropriate dose of phenibut depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for phenibut. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.

View References


  • Ahuja T, Mgbako O, Katzman C, Grossman A. Phenibut (β-Phenyl-γ-aminobutyric Acid) dependence and management of withdrawal: Emerging nootropics of abuse. Case Rep Psychiatry. 2018;2018:9864285. View abstract.
  • Anon. [The influence of agonist of GABA-receptor--phenibut on behavior and respiration of rabbits in negative emotional situation]. Zh Vyssh Nerv Deiat Im I P Pavlova 2007;57:479-88. View abstract.
  • Brunner E, Levy R. Case report of physiologic phenibut dependence treated with a phenobarbital taper in a patient being treated with buprenorphine. J Addict Med. 2017 May/Jun;11(3):239-40. View abstract.
  • Downes MA, Berling IL, Mostafa A, Grice J, Roberts MS, Isbister GK. Acute behavioural disturbance associated with phenibut purchased via an internet supplier. Clin Toxicol (Phila). 2015;53(7):636-8. View abstract.
  • Hardman MI, Sprung J, Weingarten TN. Acute phenibut withdrawal: A comprehensive literature review and illustrative case report. Bosn J Basic Med Sci. 2019;19(2):125-129. View abstract.
  • Isoardi KZ, Kulawickrama S, Isbister GK. Severe phenibut poisoning: An adolescent case cluster. J Paediatr Child Health. 2020;56(2):330-331. View abstract.
  • Joshi Y, Friend S, Jimenez B, Steiger L. Dissociative intoxication and prolonged withdrawal associated with phenibut: a case report. J Clin Psychopharmacol 2017;37(4):478-80. View abstract.
  • Li W, Madhira B. Phenibut (beta-phenyl-gamma-aminobutyric acid) psychosis. Am J Therapeut 2017;24(5):e639-640. View abstract.
  • Magsalin RM, Khan AY. Withdrawal symptoms after internet purchase of phenibut (beta-phenyl-gamma-aminobutyric acid HCl). J Clin Psychopharmacol. 2010 Oct;30(5):648-9. View abstract.
  • McCabe DJ, Bangh SA, Arens AM, Cole JB. Phenibut exposures and clinical effects reported to a regional poison center. Am J Emerg Med. 2019;37(11):2066-2071. View abstract.
  • O'Connell CW, Schneir AB, Hwang JQ, Cantrell FL. Phenibut, the appearance of another potentially dangerous product in the United States. Am J Med. 2014 Aug;127(8):e3-4. View abstract.
  • Owen DR, Wood DM, Archer JR, Dargan PI. Phenibut (4-amino-3-phenyl-butyric acid): Availability, prevalence of use, desired effects, and acute toxicity. Drug Alcohol Rev. 2016 Sep;35(5):591-6. View abstract.
  • Perfilova VN, Tiurenkov IN, Berestovitskaia VM, Vasil'eva OS. [Cardioprotective effect of GABA derivatives in acute alcohol intoxication]. Eksp Klin Farmakol 2006;69:23-7. View abstract.
  • Rod W, Kudryk A, Brunetti L, Sun N, Nguyen M. Phenibut withdrawal management in the setting of concomitant kratom and alcohol dependence. Critical Care Med 2018;46(1):451.
  • Samokhvalov AV, Paton-Gay CL, Balchand K, Rehm J. Phenibut dependence. BMJ Case Rep. 2013 Feb 6;2013. Pii: bcr2012008381. View abstract.
  • Sankary S, Canino P, Jackson J. Phenibut overdose. AM J Emerg Med. 2017 Mar;35(3):516.e1-516.e2. View abstract.
  • Shul'gina GI, Ziablitseva EA. [Effect of the GABA derivative phenibut on learning]. Vestn Ross Akad Med Nauk 2005;(2):35-40. View abstract.
  • Talalaenko AN, Krivobok GK, Pankrat'ev DV, Goncharenko NV. Neurochemical mechanisms of the dorsal pallidum in the antiaversive effects of anxiolytics in various models of anxiety. Neurosci Behav Physiol 2006;36:749-54. View abstract.
  • Talalaenko AN, Pankrat'ev DV, Bulgakova NP. [Neurochemical features of the ventral pallidum in realization of the antiaversive effects of anxiolytics in different models of anxiety]. Eksp Klin Farmakol 2006;69:6-11. View abstract.
  • Tarakanov IA, Tarasova NN, Belova EA, Safonov VA. [Effect of phenibut on the respiratory arrest caused by serotonin]. Eksp Klin Farmakol 2006;69:28-32. View abstract.
  • Tiurenkov IN, Bagmetov MN, Epishina VV, et al. [Comparative evaluation of the neuroprotective activity of phenibut and piracetam under experimental cerebral ischemia conditions in rats]. Eksp Klin Farmakol 2006;69:19-22. View abstract.
  • Tiurenkov IN, Voronkov AV, Borodkina LE. [Effect of phenibut on the behavior of experimental animals under conditions of voluntary chronic alcoholism]. Eksp Klin Farmakol 2005;68:42-5. View abstract.
  • Zheng KH, Khan A, Espiridion ED. Phenibut addiction in a patient with substance use disorder. Cureus. 2019;11(7):e5230. View abstract.
  • Ziablintseva EA. [The effect of GABA derivative phenibut on defensive conditioning and internal inhibition]. Zh Vyssh Nerv Deiat Im I P Pavlova 2006;56:236-41. View abstract.

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CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.

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