Rankings / Mood, Anxiety & Stress
Phenibut (β-phenyl-GABA)
Mood, Anxiety & Stress · GABA-B agonist (with weak GABA-A activity)
Tier D
Bottom line
Read Off Label grades Phenibut (β-phenyl-GABA) as D (2.9/10) based on weak evidence, moderate benefit magnitude, and a high-risk safety profile.
Popular among biohackers for social anxiety / public speaking / occasional use.
Typical use: 250-1000 mg PO no more than 1-2x/week (definitively NOT daily) — Russia (Rx — Anvifen, Noofen); not FDA-approved in US; not a lawful dietary supplement ingredient; sold as research chemical; UK/Australia controlled.
What this is
Popular among biohackers for social anxiety / public speaking / occasional use. Tolerance to anxiolytic effect develops within days; rebound anxiety on cessation. Severe withdrawal protocol-dependent (taper with baclofen as cross-tolerant agent). Highest-risk substance commonly recommended in nootropic forums. FDA April 2026 Addall alert found phenibut in a dietary supplement and reiterated addiction, withdrawal, loss of consciousness, and dangerous interaction risks. Use 1-2x/week MAX or risk dependence.
Mechanism
Russian-developed (1960s) GABA analog with a phenyl ring that allows BBB penetration; full GABA-B receptor agonist (similar to baclofen) plus weak GABA-A modulation; anxiolytic, prosocial, mildly euphoric at higher doses
Dose & route
250-1000 mg PO no more than 1-2x/week (definitively NOT daily)
Citations
- https://pubmed.ncbi.nlm.nih.gov/30707892/
- https://pubmed.ncbi.nlm.nih.gov/30457251/
- https://pubmed.ncbi.nlm.nih.gov/29381102/
- https://www.fda.gov/food/alerts-advisories-safety-information/fda-advises-consumers-retailers-and-distributors-not-eat-sell-or-distribute-addall-xr-shot-or-addall
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Common questions
- Does Phenibut (β-phenyl-GABA) work?
- Read Off Label rates the evidence for Phenibut (β-phenyl-GABA) as Weak and the benefit magnitude as moderate, producing an overall grade of D (2.9/10). Popular among biohackers for social anxiety / public speaking / occasional use.
- Is Phenibut (β-phenyl-GABA) safe?
- Phenibut (β-phenyl-GABA) has a high risk profile in published human data. Legal status: Russia (Rx — Anvifen, Noofen); not FDA-approved in US; not a lawful dietary supplement ingredient; sold as research chemical; UK/Australia controlled. This is not medical advice — see the disclaimer.
- What is the typical dose for Phenibut (β-phenyl-GABA)?
- 250-1000 mg PO no more than 1-2x/week (definitively NOT daily)
- How does Phenibut (β-phenyl-GABA) work?
- Russian-developed (1960s) GABA analog with a phenyl ring that allows BBB penetration; full GABA-B receptor agonist (similar to baclofen) plus weak GABA-A modulation; anxiolytic, prosocial, mildly euphoric at higher doses
This is an independent synthesis of published research by a non-clinician. Scores are opinions supported by citations, not prescriptions. See the full disclaimer and methodology for how this score was produced and what it does and doesn't mean.