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Street name

Bonsai, Bonsai supersleep, Fenazepam

General Info

Phenazepam is a powerful benzodiazepine, which are drugs referred to as minor tranquillisers because they relieve tension and anxiety, and help the user feel calm and relaxed. Phenazepam has been reported as approximately five times stronger than Valium (another well known tranquilliser), so it is easy to take too much and overdose. Phenazepam is not used in the UK as a medicine, but it is used in Russia to treat epilepsy and neurological disorders. Phenazepam was previously sold and marketed as a ‘legal high’ or as fake Valium.


  • Provides a sedative effect, relieving tension and anxiety, and making the user feel calm and relaxed
  • Causes a loss of coordination, dizziness and drowsiness.
  • Big doses can make a user forgetful and send them to sleep or potentially put them into a coma.


  • Phenazepam is a depressant so mixing it with other depressant drugs like Heroin, other tranquillisers or alcohol, can lead to an accidental overdose and possibly death
  • It takes a couple of hours for the effects of Phenazepam to kick in. This means that there is a risk that people will re-dose before they feel the effects and increase their risk of overdosing
  • Phenazepam is used to make fake Valium. People have taken what they thought was a normal Valium dose, but is in fact a high dose of Phenazepam, and have ended up in hospital.


Class C