What is Phenibut (Phenylgan or Noofen)?

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Last updated: April 29, 2025View editorial policy

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From the Research

Phenibut is a synthetic central nervous system depressant that should be used with caution due to its high addiction potential, severe withdrawal symptoms, and dangerous interactions with alcohol and other depressants. Phenibut works by binding to GABA-B receptors in the brain, similar to the neurotransmitter GABA, which produces calming effects [ 1 ]. It is primarily used in Russia and some Eastern European countries to treat anxiety, insomnia, depression, and post-traumatic stress disorder, but is not approved for medical use in the United States or most Western countries.

Key Points

  • Phenibut is a nootropic drug that exerts anxiolytic and antinociceptive effects by acting on the GABAB receptor and the α2-δ subunit of voltage-dependent calcium channels [ 1 ].
  • Typical therapeutic doses range from 250-1000mg per day, divided into 2-3 doses [ 1 ].
  • Phenibut carries significant risks including high addiction potential, severe withdrawal symptoms, and dangerous interactions with alcohol and other depressants [ 2 ].
  • Tolerance develops quickly, often leading to dose escalation [ 2 ].
  • Due to these concerns, phenibut is sold as an unregulated supplement in many countries, creating safety issues as users may not receive proper guidance on dosing or risks [ 3 ].

Risks and Consequences

  • Phenibut withdrawal can cause severe symptoms such as delirium, hallucinations, and seizures [ 3 ].
  • The use of phenibut has been associated with increased risk of respiratory failure, intubation, and intensive care unit admission [ 4 ].
  • Phenibut exposure calls to poison centers have increased over the past five years, with CNS depression being a common symptom [ 4 ].

Treatment and Management

  • Treatment of phenibut withdrawal typically involves the use of benzodiazepines, baclofen, or phenobarbital, as individual agents or in various combinations [ 5 ].
  • Ancillary medications such as antipsychotics, dexmedetomidine, gabapentin, and pregabalin may also be used [ 5 ].
  • Consultation with an addiction specialist or toxicologist is recommended in cases of phenibut intoxication or withdrawal [ 5 ].

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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