Also known as "4-Amino-3-Phenylbutyric Acid," Phenibut is a non-prescription pharmaceutical that is actually a GABA molecule with the addition of a phenyl group. Russian researchers discovered that by changing GABA into 4-Amino-3-Phenylbutyric Acid, it was able to cross more easily into the nervous system & across the blood-brain barrier. Since it is a GABA, an inhibitory neurotransmitter, derivative, Phenibut increases GABA levels.
 
Phenibut is a white crystalline powder and the taste is very sour. It is readily soluble in water, soluble in alcohol, and the pH of a 2.5% water solution is between about 2.3 and 2.7.