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Phenibut

Group: Depressants
Nicknames: Anvifen, Fenibut, Bifren, Noofen, Phenigamma, Phenigama, Fenigam, F-but
Last reviewed: October 2026

Harm Reduction

  • Start low, go slow: Take a small amount and wait until you can feel the effects before taking more/anything else
  • Try not to use alone: If something goes wrong, someone is there to get help
  • Be careful mixing: Mixing phenibut with other depressants increases overdose risk – avoid if you can, otherwise take less of each, as they can increase the effects and risks
  • Carry naloxone: In case opioids are in the mix
  • Test your stuff: Find out how to send a sample to WEDINOS for testing here: https://www.wedinos.wales or pick up some test strips at our Harm Reduction Hub
  • Don’t suddenly stop taking them, or you may start to experience symptoms of withdrawal: these can range from a return of your original symptoms (possibly even worse than before) to totally new symptoms.
  • If you have become physically dependent on phenibut, the symptoms of abruptly stopping are likely to be even worse. It’s important to get proper medical advice on how to reduce your intake slowly.
  • It’s also possible to become psychologically dependent on the drug (feeling like you need it all the time). If you think this is happening, see your doctor as soon as possible, but don’t suddenly stop taking it.

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