How long does it take for Phenibut to kick in?

Phenibut (phenyl-gamma-aminobutyric acid) is a neuropsychotropic substance discovered and introduced into clinical practice in Russia in the 1960s where it was widely used to relieve tension, anxiety, anguish and to improve sleep for neurotic patients.

Similar in structure to GABA — a natural neurotransmitter in the brain that controls anxiety and sleep — Phenibut has nootropic and anxiolytic properties. Its only difference to GABA is a small “phenyl” ring (hence the name), which helps Phenibut get into the brain (GABA, on the other hand, can’t get in).