data + articles · 2 listed
newest 2021spec sheet10 rows
F-Phenibut (fluorophenibut) is a fluorinated analog of phenibut, a GABA-B agonist used as an anxiolytic and sleep aid; it's presumed to share phenibut's mechanism and is reported to be more potent. It produces anxiety relief, sociability, and sedation. Its real danger is fast tolerance and a severe, protracted dependence with a withdrawal that can rival benzodiazepine withdrawal.
- Anxiety relief
- Sociability and mood lift
- Improved sleep
- Fast tolerance
- Severe, protracted dependence and withdrawal
- Sedation and next-day grogginess
- Overshoot from slow onset
Mechanism
F-Phenibut is presumed to act, like phenibut, primarily as an at the -B receptor (a metabotropic receptor for the brain's main inhibitory neurotransmitter), which produces its anxiolytic and sedating effects; phenibut also has some activity at voltage-dependent calcium channels. The fluorine substitution is thought to increase potency and possibly lipophilicity. The GABA-B agonism is also why tolerance and dependence develop so readily with regular use.
receptor fingerprint
-B receptorAgonist
Voltage-dependent calcium channelsPresumed weak modulation (via phenibut-like activity)
Dosingtypical ranges, not medical advice
interested in protocols and clinical dosages? make an account to see them! ^_^
Safetyrisks and cautions, not medical advice
Tolerance builds fast, pushing people to escalate the dose, and physical dependence can develop within days to weeks; withdrawal is notoriously severe and drawn out, with intense anxiety, insomnia, and sometimes psychosis or seizures, so discontinuation should be a supervised taper. Combined with alcohol, benzodiazepines, or opioids it deepens sedation and respiratory depression dangerously. As a research chemical it's often mis-measured, and its delayed onset invites redosing and overshoot. Not medical advice.
Subjective profileweighing the evidence above
Avoid it. Making phenibut more potent mostly means tolerance builds faster and dependence goes deeper, with a protracted withdrawal that can include psychosis and seizures and needs a supervised taper. No amount of calm or better sleep is worth that trade, and mis-measured research chemical powder makes it worse.
Resources
This entry is here for reference.
Research
- 1.Phenibut (β-Phenyl-γ-Aminobutyric Acid): an Easily Obtainable "Dietary Supplement" With Propensities for Physical Dependence and Addiction
- 2.Sedative-Hypnotic Agents That Impact Gamma-Aminobutyric Acid Receptors: Focus on Flunitrazepam, Gamma-Hydroxybutyric Acid, Phenibut, and Selank
2 listed here; entry last updated August 2026
Reviews
My notesprivate to this device
FAQ
How does F-phenibut differ from phenibut?
It's the fluorinated analog, presumed to share the GABA-B mechanism but reported to be more potent, so the same risks arrive at smaller amounts.
Why is dependence such a concern?
GABA-B agonists like this build tolerance quickly, and withdrawal can be severe and long-lasting, with anxiety, insomnia, and sometimes seizures or psychosis.
Why is the slow onset a problem?
Because effects take hours to build, people often redose too soon and end up far more sedated than intended.
Adverse effects
- Fast tolerance
- Severe, protracted dependence and withdrawal
- Sedation and next-day grogginess
- Overshoot from slow onset