Ingredient Type: Amino acid (neurotransmitter)Also Known As: Gamma-aminobutyric acid, ?-Aminobutyric acid, 4-aminobutanoic acidGABA (Gamma-Aminobutyric Acid) is a neurotransmitter found in the body. Its chief role is thought to be the inhibition of nerve excitability throughout the nervous system and the brain.GABA is most popularly used in health supplements today to help promote mental clarity and relaxation.