γ-Aminobutyric acid (GABA) is a kind of natural amino acid, which is the chief inhibitory neurotransmitter in the mammalian central nervous system. It plays a role in regulating neuronal excitability throughout the nervous system. In humans, GABA is also directly responsible for the regulation of muscle tone. When the level of GABA in the brain decreases below a certain level seizures and other neurological disorders may occur. GABA can act as a natural calming and anti-epileptic agent in the brain, also increases levels of HGH, which is desirable to most adults since this hormone allows children and teenagers to grow and gain weight increase muscle mass without putting on extra pounds.USA