Phenibut is a prescription anxiolytic in Russia, available in Western Europe over the internet as a “dietary supplement.” It acts as a GABA-B agonist (similar to GHB, but with a long duration of 6–12 h).
Clinical risks in combination:
- Double GABAergic depression — amplified exponentially with alcohol, benzos or GHB
- Respiratory depression possible, especially at higher doses
- Severe withdrawal symptoms with chronic use — withdrawal resembles alcohol withdrawal and can be life-threatening (seizures, delirium)
In the DIY and nootropic context, phenibut is often underestimated. It rapidly develops tolerance and dependence. With longer-term use, medically supervised withdrawal makes sense.
Practical notes:
- Don’t combine phenibut with alcohol — this is one of the most common phenibut-related emergency room visits
- Don’t exceed the maximum dose (typical recommendation: 500–1000 mg per day, not over several days)
- If you suspect chronic use: seek medical advice, don’t stop abruptly
We recommend not combining phenibut with other GABAergic substances.