Gamma-Aminobutyric Acid Unit Converter

Gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the central nervous system. It works by calming neural activity, counterbalancing glutamate (the brain's primary excitatory signal). Roughly 40% of the inhibitory synapses in the adult brain use GABA.

A plasma GABA test measures the concentration of this amino acid circulating in your blood. Although GABA is best known for its role in the brain, it is also produced in the pancreas, gut, and other tissues, so plasma levels reflect both neuronal and peripheral sources.

GABA is synthesized from glutamate by the enzyme glutamic acid decarboxylase (GAD), which requires vitamin B6 as an essential cofactor. The brain is the primary source, but GABA is also produced in significant amounts by pancreatic beta cells, enteric neurons in the gut, gut bacteria, kidneys, and immune cells.