F-Phenibut
F-Phenibut is a central nervous system depressant of the gabapentinoid class and a close structural analog of both phenibut and baclofen. It is a derivative of the neurotransmitter GABA, featuring a fluorine-substituted phenyl group that allows it to cross the blood-brain barrier. Compared to phenibut, it is reported to have a faster onset, significantly greater potency, and shorter duration. Very little is known about its toxicity or addiction potential.
Contents
Dosage & Duration
Dosage
Duration
Subjective Effects
The experience closely resembles that of phenibut, reflecting the compound's shared mechanism as a GABAB receptor agonist, but arrives with greater potency owing to the fluorine substitution. It is a predominantly depressant and anxiolytic state with little in the way of sensory alteration, characterized by relief from anxiety, easy sociability, and physical relaxation that deepens into sedation as the dose increases.
Physical
Muscle relaxation and a relaxed, heavy body feeling are the primary physical effects, progressing to sedation and impaired coordination at higher doses.
Depressant
Cognitive
The headspace is calm and disinhibited, with social ease and a mild sense of well-being replacing anxious thought patterns rather than any pronounced intoxication at lower doses.
Emotional
Social
Reagent Testing
Loading reagent data
Pharmacology
Pharmacodynamics
F-Phenibut acts as an agonist of the GABA-B receptor with selectivity over the GABA-A receptor. It is less potent than baclofen at the GABA-B receptor but more potent than phenibut. F-Phenibut may also bind to the α2δ-1 subunit of voltage-gated calcium channels in a manner similar to other gabapentinoids, which could reduce the release of several excitatory neurotransmitters including glutamate, substance P, acetylcholine, and norepinephrine.
Pharmacokinetics
Tolerance
GABAergic depressants, Phenibut and related analogues
Harm Potential
Addiction & Dependence
Psychological
ModerateModerately psychologically addictive, particularly with heavy or frequent use. The rapid onset compared to phenibut facilitates compulsive redosing, which is reported to be highly pronounced. The combination of reduced inebriation with greater euphoria relative to other GABAergic depressants contributes to elevated abuse potential.
Physical
ModeratePhysical dependence can develop with regular use over several weeks or longer. Withdrawal symptoms may include severe anxiety, nervousness, tremors, agitation, rapid heartbeat, fatigue, nausea, vomiting, and insomnia. Gradual dose reduction is recommended to avoid withdrawal effects.
Psychosis Risk
Psychosis is reported as a potential withdrawal symptom following cessation of prolonged or heavy use, similar to phenibut. Not typically associated with acute intoxication at standard doses.
History & Culture
F-Phenibut, designated by the developmental code name CGP-11130, is a GABA analogue that was investigated as a potential pharmaceutical agent but was never marketed. The compound belongs to a family of phenyl-substituted GABA derivatives that includes baclofen, tolibut, and phenibut, all of which…
Legality
By Country
Automated synthesisInformation aggregated and synthesized using an autonomous workflow built by Josie Kins.
Suggest an edit
Spotted a mistake, an outdated claim, or something missing from the F-Phenibut article? Send the editors a private note. Feedback lands in a moderation queue and is never shown on the site.