Racemic phenibut (beta-phenyl-gamma-aminobutyric acid or 4-amino-3-phenylbutyric acid) is a neuropsychotropic drug that was discovered and introduced into clinical practice in Russia in the 1960s. In pharmacological tests of locomotor activity, antidepressant and pain effects, S-phenibut was inactive. In contrast, R-phenibut turned out to be two times more potent than racemic phenibut in most of the tests. Racemic phenibut and R-phenibut demonstrated an affinity for GABAB receptors, in contrast, S-phenibut was not able to bind receptors. Pharmacological activity of racemic phenibut relies on R-phenibut and this correlates to the binding affinity of enantiomers of phenibut to the GABAB receptor. Both S- and R-phenibut bind to the α2-δ subunit of voltage-dependent calcium channels and exert gabapentin-like anti-nociceptive effects. In addition S-isomer was found to be a substrate of gamma-aminobutyric acid aminotransferase, however, the R-isomer is a competitive inhibitor.

Hopantenic acid (homopantothenic acid) is a central nervous system depressant. Formulated as the calcium salt, it is used as a pharmaceutical drug in the Russian Federation under the brand name Pantogam. In Russia it is widely used to treat a variety of neurological, psychological and psychiatric conditions. The drug has been on the pharmaceutical market since 1979 and has been proven to be safe even for children from 3 years old upwards. Hopantenic acid is a natural forming substance, has some of the lowest side effects and considered to be very safe. Use Pantogam to treat a wide variety of cognitive and nervous system disorders with combined sedative and mild stimulant effect. Hopantenic acid is not approved for use in Europe or the United States. GABA receptor agonist.

Racemic phenibut (beta-phenyl-gamma-aminobutyric acid or 4-amino-3-phenylbutyric acid) is a neuropsychotropic drug that was discovered and introduced into clinical practice in Russia in the 1960s. In pharmacological tests of locomotor activity, antidepressant and pain effects, S-phenibut was inactive. In contrast, R-phenibut turned out to be two times more potent than racemic phenibut in most of the tests. Racemic phenibut and R-phenibut demonstrated an affinity for GABAB receptors, in contrast, S-phenibut was not able to bind receptors. Pharmacological activity of racemic phenibut relies on R-phenibut and this correlates to the binding affinity of enantiomers of phenibut to the GABAB receptor. Both S- and R-phenibut bind to the α2-δ subunit of voltage-dependent calcium channels and exert gabapentin-like anti-nociceptive effects. In addition S-isomer was found to be a substrate of gamma-aminobutyric acid aminotransferase, however, the R-isomer is a competitive inhibitor.

Hopantenic acid (homopantothenic acid) is a central nervous system depressant. Formulated as the calcium salt, it is used as a pharmaceutical drug in the Russian Federation under the brand name Pantogam. In Russia it is widely used to treat a variety of neurological, psychological and psychiatric conditions. The drug has been on the pharmaceutical market since 1979 and has been proven to be safe even for children from 3 years old upwards. Hopantenic acid is a natural forming substance, has some of the lowest side effects and considered to be very safe. Use Pantogam to treat a wide variety of cognitive and nervous system disorders with combined sedative and mild stimulant effect. Hopantenic acid is not approved for use in Europe or the United States. GABA receptor agonist.