Complete dosage information for Phenibut — threshold, light, common, strong, and heavy dose ranges across 1 route of administration.
Full Phenibut profileImportant Safety Notice
Dosage information is for harm reduction purposes only. Individual sensitivity varies greatly. Always start with the lowest effective dose and work your way up slowly. Never eyeball doses — use a milligram scale.
## Overdose Profile Fatal overdose from phenibut alone is uncommon but has been documented in the medical literature, typically at very high doses (7g+). The clinical picture of phenibut overdose in isolation primarily involves excessive CNS depression: deep sedation progressing to unresponsive stupor, respiratory depression (usually mild to moderate with phenibut alone), hypothermia, and metabolic acidosis. ## Combination Overdose The risk of fatal outcome increases dramatically when phenibut is combined with other CNS depressants. The most dangerous combinations are: - **Phenibut + alcohol**: synergistic CNS depression with high risk of respiratory compromise, aspiration, and death - **Phenibut + opioids**: additive respiratory depression — this combination has produced numerous fatalities - **Phenibut + benzodiazepines**: excessive GABA-ergic activity producing profound sedation, respiratory depression, and cardiovascular instability - **Phenibut + GHB/GBL**: both are GABA-B agonists; the combination produces rapid onset of unconsciousness with respiratory arrest risk ## Overdose Symptoms - Extreme drowsiness progressing to stupor or coma - Nausea and vomiting (aspiration risk if consciousness is impaired) - Severe motor impairment and loss of coordination - Slurred or absent speech - Respiratory depression (slow, shallow breathing) - Hypothermia (decreased body temperature) - Tachycardia or bradycardia - In severe cases: metabolic acidosis, rhabdomyolysis, renal failure ## Treatment There is **no specific antidote** for phenibut overdose. Management is entirely supportive: - Airway management and mechanical ventilation if respiratory depression is severe - Cardiovascular monitoring and support - Correction of metabolic acidosis with sodium bicarbonate if indicated - Activated charcoal if administered within 1 hour of ingestion (limited evidence) - Hemodialysis may be considered in severe cases, as phenibut's moderate water solubility and limited protein binding make it theoretically amenable to dialytic removal, though clinical experience is limited
A common Oral dose of Phenibut is 500–1000 mg.
The threshold dose for Phenibut via Oral is approximately 100 mg.
Phenibut typically lasts 15–24 hours via Oral.
