Phenibut (phenyl-gamma-aminobutyric acid) is a derivative of GABA (gamma aminobutyric acid) that crosses the blood-brain barrier easily, due to the presence of a methyl ring. Since it was discovered and introduced into clinical practice in Russia in the 1960s, iPhenibut has been used there to relieve anxiety and improve sleep in neurotic patients. It has both nootropic (cognition-enhancing) and anxiolytic properties and is often compared to diazepam, baclofen and piracetam.

Phenibut’s capacity for relieving anxiety has been demonstrated in a number of animal models. Its mechanism of action is similar to that of several drugs known to reduce anxiety in humans. Animal studies conducted to compare its profile to that of diazepam and piracetam have shown that phenibut has a similar – albeit weaker - tranquillizing effect to that of diazepam. It also has sedative and muscle-relaxing effects, though again, these effects are weaker than those of diazepam.

In Russia, phenibut is commonly used to treat a number of neuroses including post-traumatic disorder, stammering and insomnia. Studies show that doses of 0.25-0.5g, given three times a day, improve intellectual function and physical strength while reducing fatigue and asthenia in neurotic and psychotic patients. Its effectiveness at treating psychological and psychiatric disorders has been compared to that of diazepam.

Animal and human studies support a nootropic action for phenibut, similar - though weaker - to that of piracetam.

As with all nootropics, phenibut has a neuroprotective effect. It protects dopaminergic neurons and improved the condition of patients being treated for Parkinson’s disease.

Phenibut also appears to have beneficial properties relating to tobacco or alcohol dependency. It successfully helped smokers wean themselves off tobacco, its relaxant effect preventing the anxiety which often occurs in such situations. Phenibut is ideal for short periods of stress or anxiety but not for long-term use. The body develops tolerance to many of the effects of Phenibut (though probably not its nootropic effect). The first signs of such tolerance can appear as early as five days into treatment. For this reason it is generally used for one- to two-week periods only.