Phenazepam is a benzodiazepine first developed in the Soviet Union in 1975. It is prescribed in Russia and other countries for psychiatric conditions including anxiety and schizophrenia, as well as for epilepsy, alcohol withdrawal, and surgical premedication. Phenazepam is notable for its exceptionally long duration of action and high potency. The substance has gained notoriety for problematic recreational use, with numerous reports of compulsive redosing and reckless behavior due to its subtle onset and extended effects.
Феназепам molecular structure diagram from the DrugsPRO substance library.
Also known as: Fenaz, Panda, Bonsai, Soviet benzo, Bromdihydrochlorphenylbenzodiazepine, Fenazepam, Phenzitat
Classification
Chemical: Benzodiazepine
Psychoactive: Depressant
Tag: Anxiolytic
Tag: GABAergic
Tag: Habit-Forming
Tag: Muscle Relaxant
Tag: Research-Chemical
Effects
Ataxia
Sedation
Muscle Relaxation
Hiccups
Anxiolytic
Sedative
Anxiety Suppression
Amnesia
Dizziness
Memory Impairment
Confusion
Euphoria
Double Vision
Disinhibition
Dulled Perception
Routes of Administration
Oral
Dosage
Heavy: 2-4 mg
Light: 0.5 – 1 mg
Common: 1 – 2 mg
Strong: 2 – 3 mg
Threshold: 0.25 mg
Duration
Onset: 0.33-1.5 h
After Effects: 24-96 h
Peak: 2-4 h
Offset: 24-72 h
Total Duration: 12-72 h
Sublingual
Dosage
Heavy: 4+ mg
Light: 0.5-1 mg
Common: 1-2 mg
Strong: 2-4 mg
Threshold: 0.25 mg
Duration
Onset: 0.25-1 h
Peak: 2-3.5 h
Offset: 24-60 h
After Effects: 24-96 h
Total Duration: 12-60 h
Insufflated
Dosage
Heavy: 2+ mg
Light: 0.5 mg
Common: 0.5-1 mg
Strong: 1-2 mg
Threshold: 0.25 mg
Duration
No data available for this section yet.
Harm Reduction
Check interactions before mixing substances, pay attention to dose spacing and hydration, and treat all dosage guidance as approximate rather than guaranteed safe.
Sources
Substance data is aggregated from the following public harm-reduction and reference sources.
This static page is intended as a readable non-JS and prerender-friendly library export.
Get the full DrugsPRO experience
Open the interactive DrugsPRO app for search, saved items, interactions, and deeper harm reduction tools.
Get the PRO test kit. The simple, quick and reliable drug checking test kit. Visit https://protestkit.eu
Phenazepam - DrugsPRO vodič o supstancama
Phenazepam: Phenazepam is a benzodiazepine first developed in the Soviet Union in 1975. It is prescribed in Russia and other countries for psychiatric conditions including anxiety and schizophrenia, as well as for epilepsy, alcohol withdrawal, and surgical premedication. Phenazepam is notable for it
