Rankings / Cognitive — Nootropics
Phenibut (β-phenyl-GABA)
Cognitive · GABA-B agonist (with weak GABA-A activity)
Tier D+
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. 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/
Links go to the source. If a link is dead or you want something re-checked, let me know.
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.