Back to Phenibut

Safety question

Is Phenibut safe?

High risk — avoid casual recreational use. Phenibut scores 1/5. Serious adverse events are documented in the clinical or coroner record. Use is appropriate only for narrowly-indicated medical purposes under specialist supervision.

Safety score

1 / 5

Evidence grade

C

Severe reactions on file

1

Pubmed cites

110

Key facts

typical dose
250–1000 mg
dose frequency
max 1-2x/week
timing
before stressor
with food
optional
onset
120 minutes
half-life
5 hours
safety score
1/5
evidence grade
C
class
research_chemical
PubMed citations
110
legal status (US)
Research-chemical category
legal status (UK)
Research-chemical category
legal status (EU)
Research-chemical category
legal status (AU)
Banned
restrictions
US (not a legal supplement); AU; UK PSA 2016
primary mechanism
Direct agonist at GABA-B receptors — the same mechanism as the prescription anti-spasticity drug baclofen.

Common side effects

Severe reaction risks

Phenibut has the following documented severe adverse reactions: Severe dependence/withdrawal. These are rare but require immediate medical attention if they occur.

Banned or restricted in

  • US (not a legal supplement)
  • AU
  • UK PSA 2016

Restrictions can include outright bans, prescription-only classification, anti-doping prohibitions (WADA), or supplement-marketing restrictions. Check your local regulator before purchasing.

Who should not take Phenibut

What "safe" means here

Our safety scoring reflects (a) published clinical and observational literature on healthy-adult use at standard supplement doses, (b) the spectrum of adverse-event reports in the medical and supplement-pharmacovigilance record, and (c) the regulatory status across major jurisdictions. It does notreflect long-term outcomes in populations that haven’t been studied, and it does not substitute for clinical judgement applied to your individual situation.

A 5/5 score does not mean “no risk” — it means risk has been quantified as low in healthy adults at usual doses. Idiosyncratic and allergic reactions are possible with virtually any compound, including those we rate highest.

Full mechanism, citations, and dose guidance for Phenibut are on the main reference page — see Phenibut. For the dose-by-dose breakdown, see Phenibut dosage. To check stack interactions, use the interaction checker.

This page is informational. It is not medical advice and does not establish a clinician-patient relationship. Individual risk varies with genetics, medications, pre-existing conditions, and dose. Always consult a qualified clinician before starting a new compound. See our full disclaimer and terms.