γ-Amino-β-hydroxybutyric acid (GABOB) (brand names Gamibetal, Gabomade, Aminoxan, Bogil, Diastal, Gabimex, Gaboril, Kolpo), or β-hydroxy-γ-aminobutyric acid (β-hydroxy-GABA), is an anticonvulsant which is used for the treatment of epilepsy in Europe, Japan, and Mexico. It is also an endogenous active metabolite and analogue of the neurotransmitter γ-aminobutyric acid (GABA), and for this reason, may function as a neurotransmitter itself. Relative to GABA, GABOB has more potent inhibitory effects on the central nervous system, perhaps due to its greater capacity to cross the blood-brain-barrier. However, GABOB is of relatively low potency as an anticonvulsant when used by itself, and is more useful as an adjuvant treatment used alongside another anticonvulsant. GABOB has two stereoisomers,