Phenibut (β-phenyl-GABA) C
A prescription drug with a high risk of dependence; it is not a supplement
Citable fact
«Phenibut (β-phenyl-GABA)» — evidence level C. Dosage: In medicine, doses of 250–500 mg 1–3 times a day are used under medical supervision. For sports purposes, arbitrary doses are used, often 1–3 g and more, which sharply increases the risk of dependence, delirium and overdose. There is no safe dose for intake “as a supplement”. Source: PMID 38112312, permanent link to the source in the list below.
How it works
A GABA derivative acting mainly on GABA-B receptors and, at high doses, affecting the GABA-A and dopamine systems. It produces an anxiolytic and sedative effect, with a half-life of about 5 hours.
Dosage and intake
In medicine, doses of 250–500 mg 1–3 times a day are used under medical supervision. For sports purposes, arbitrary doses are used, often 1–3 g and more, which sharply increases the risk of dependence, delirium and overdose. There is no safe dose for intake “as a supplement”.
There is no justified time of intake. Dependence has been described already with intake 2–3 times a week, so no regimen can be considered protective against it.
Forms
The form is phenibut hydrochloride (tablets, powder). In pharmacies it is a prescription drug; on the internet it is sold as a “supplement” or “nootropic”, which does not make it a dietary supplement.
What is confirmed
- Clinical studies show a short-term anxiolytic effect; there are no sports studies of performance
- There are no sports studies assessing strength, body weight or fat burning
- Clinical series describe cases of severe withdrawal after 2–3 weeks of regular use — this is the most reproducible fact about the drug
Adverse effects and limitations
- Dependence develops quickly, including with intake 2–3 times a week
- Withdrawal syndrome is severe: delirium, hallucinations, seizures, tachycardia, hyperthermia; hospitalization is required, and fatal outcomes have been described
- Not approved as a medicine in the US and most EU countries and is not a dietary supplement: sale as a supplement is illegal
- Dangerous combinations with alcohol, benzodiazepines and opioids: CNS and respiratory depression up to coma
Interactions
- Alcohol, benzodiazepines, barbiturates, opioids, gabapentin — pronounced CNS and respiratory depression
- Psychotropic drugs, including clomipramine: cases of delirium have been described
- Abrupt discontinuation after long-term use without medical supervision is life-threatening
Who must not use it
- Under 18 years: Contraindicated. In countries where the drug is registered, it is prescribed to children only for strict medical indications.
- Pregnancy and lactation: Contraindicated in pregnancy and lactation.
- history of alcohol or drug dependence
- epilepsy
- severe hepatic and renal failure
- concurrent use of sedative drugs
- pregnancy and lactation
Sources
- A systematic review of phenibut withdrawal focusing on complications, therapeutic approaches, and single substance versus polysubstance withdrawal · Feldman R, Autry B, Dukes J · Clinical toxicology (Philadelphia, Pa.), 2023 · PMID 38112312
- Phenibut Dependence and Withdrawal · Sethi R, Ravishankar DA, Nagireddy R · The primary care companion for CNS disorders, 2021 · PMID 34000148
See also
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