F-Phenibut
4-fluorophenibut
Standing risks
| Risk | Recorded values | Confidence | Article section |
|---|---|---|---|
| Dangerous withdrawal, taper carefully |
| low | View in article: Dangerous withdrawal, taper carefully |
| Compulsive use risk, monitor frequency |
| low | View in article: Compulsive use risk, monitor frequency |
Lethal interactions
| Combination | Type | Severity | Mechanisms | Confidence |
|---|---|---|---|---|
| GHB, GBL | Drug class | lethal | 2 | high |
| Opioids | Drug class | lethal | 2 | high |
Dangerous interactions
36 dangerous interactions recorded for this substance.
See the full interactions tableContraindications
| Condition | Severity | Note |
|---|---|---|
| Respiratory | ||
| respiratory insufficiency | absolute | F-phenibut should not be used by individuals with significant respiratory impairment. GABA-B agonist-induced respiratory depression is the primary mechanism of death in phenibut-class overdose. |
| Neurological | ||
| epilepsy | relative | Individuals with seizure disorders face compounded risk during F-phenibut withdrawal. Seizures are documented in phenibut withdrawal case series. |
| Psychiatric | ||
| substance use disorders | relative | Individuals with a history of substance use disorders, particularly GABAergic substance dependence (alcohol, benzodiazepines, GHB), face elevated risk of F-phenibut dependence. |
| Renal | ||
| renal impairment | relative | Renal impairment may significantly prolong F-phenibut exposure, as the phenibut class undergoes minimal hepatic metabolism and relies on renal excretion. |
| Pregnancy & Breastfeeding | ||
| pregnancy | absolute | F-phenibut is contraindicated during pregnancy and breastfeeding. No reproductive safety data exist. GABA-B agonists cross the placenta and the risk-benefit ratio cannot be assessed. |
| Other | ||
| concurrent CNS depressant use | absolute | Concurrent use with any CNS depressant is potentially lethal. This is the primary identified cause of serious adverse outcomes in phenibut-class compounds. |