RESEARCH MONOGRAPH · KDC-MN-067

Phenibut

May 9, 2026 Kodiac biolabs Research Revised May 30, 2026 2 min read

Our opinion on this compound

63/100

Real GABA-B agonist with serious dependence liability that the supplement scene keeps pretending isn't there

Phenibut is one of the most mishandled compounds in the nootropic space and we'll say it plainly. Yes the mechanism is real (beta-phenyl-GABA, GABA-B receptor agonist, some alpha2-delta calcium channel binding at high doses similar to gabapentin), and yes the original Russian work from the Perekalin group in the 60s and the clinical use for anxiety and pediatric tic disorders is legitimate. The Soviet space program included it in cosmonaut kits for a reason.

But the way it gets sold in western nootropic circles is genuinely irresponsible. Phenibut has classic sedative-hypnotic dependence pharmacology. GABA-B agonism plus longish half-life plus tolerance development over days, not weeks, means you can build a serious physical dependence in a couple weeks of regular use, and the withdrawal syndrome looks like benzodiazepine withdrawal: anxiety, insomnia, tremor, derealization, in severe cases seizures and psychosis. ER admissions for phenibut withdrawal have been climbing for the last 5+ years.

What we like, from a pharmacology research standpoint, is that it's a tractable GABA-B agonist with reasonable oral bioavailability and a known dose-response curve. For studying GABA-B-mediated effects in animal models, phenibut is more practical than baclofen in some setups because of its better CNS penetration profile relative to peripheral activity.

What we dont like is everything about how it's marketed. Calling it a nootropic is genuinely misleading. It's not cognitive-enhancing, it's anxiolytic-sedating, and the dependence profile makes the recreational-supplement category basically dangerous.

Sourcing: the racemate is straightforward to synthesize, HPLC pure is widely available, and the R-enantiomer is the active species. Most commercial powder is racemic. Purity per se isn't the main issue here; the issue is how it gets used.

For RUO pharmacology work on GABA-B and alpha-2-delta signaling, it's a perfectly reasonable tool compound. For anything else, treat it with the same respect you'd treat a research-grade benzodiazepine, because the dependence biology is basically the same.

Evidence: 55
Mechanism: 82
Reliability: 75
Safety: 35
Sourcing: 75
Value: 60
Signal: 70
Staying power: 55

Plain-language summary Intrigue 60 / 100

Phenibut is a Russian anxiolytic that activates GABA-B receptors (the same receptors as the prescription drug baclofen). It produces anxiolysis at low doses but carries dependence and severe withdrawal risk with regular use. Not stocked by Kodiac. This monograph is provided for research and educational reference.

Intrigue 0–100 blends mechanism novelty, evidence strength, and translational potential. Kodiac editorial, not peer-reviewed.

GABA-B agonist / phenyl-GABA

A Soviet-developed phenyl-substituted GABA analog with GABA-B receptor agonism, used clinically in Russia for anxiety and sleep with documented dependence liability.

Abstract

Phenibut (4-amino-3-phenyl-butanoic acid; CAS 1078-21-3; molecular formula C10H13NO2; molecular weight 179.22) is a phenyl-substituted GABA analog developed in the Soviet Union in the 1960s at the Herzen State Pedagogical University. The phenyl substitution at the 3-position confers blood-brain barrier permeability that GABA itself lacks. Phenibut is approved in Russia, Belarus, Kazakhstan, and Latvia as Phenibut, Noofen, and Anvifen for anxiety, insomnia, asthenia, and post-traumatic stress disorder. Mechanism is primarily GABA-B receptor agonism (similar to baclofen) with secondary effects on voltage-gated calcium channels at higher doses. The (R)-enantiomer is the active component. Pharmacokinetics: plasma half-life 5 to 6 hours; rapid oral absorption. Reported research dose ranges in the literature are described in the source monograph. Phenibut has documented dependence liability with chronic high-dose use; withdrawal syndrome includes anxiety, insomnia, tremor, and rebound symptoms. The compound is sold as a research chemical/dietary supplement in the United States though regulatory classification is increasingly restrictive in some states. Investigators should be aware of the dependence potential and avoid chronic exposure.

Mechanism of action

Primary GABA-B agonist (R-enantiomer active). Voltage-gated calcium channel modulation at higher doses.

Reported research dose ranges

250 to 1500 mg (reported research dose range); significant dependence liability with chronic use.

References

Lapin I. Phenibut (beta-phenyl-GABA): a tranquilizer and nootropic drug. CNS Drug Rev 2001.

Read the full monograph

The full reference document covers compound identification, discovery and developmental history, mechanism of action, pharmacokinetics, reported research dose ranges, sourcing and quality verification, reconstitution and handling, stack interaction considerations, and a curated reference list. Available as a research-use-only PDF download.

KDC-MN-067

The full reference document is provided strictly for research use only. It reports research dose ranges from the published literature, not instructions for use in humans or animals.

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FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.

Kodiac sells research compounds for investigative use only.

Phenibut

Abstract

Mechanism of action

Reported research dose ranges

References

Read the full monograph

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Abstract

Mechanism of action

Reported research dose ranges

References

Read the full monograph

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