GABA (Gamma-AminoButyric Acid) is a depressive neurotransmitter, responsible for regulating many depressive and sedative actions in the brain. GABA plays a role in reducing neuronal excitability and is therefore critical for relaxation and sleep.
GABA activity in the brain was first recognized in the 19th century when barbiturates were first used to reduce anxiety and treat epileptic seizures (1). The advent of barbiturate use spawned the use of a wide variety of pharmacological drugs that were all found to mediate GABA receptors in the brain. GABA wasn’t used directly as a supplement; rather, GABA was targeted as an important neurotransmitter to reduce stress and anxiety (2).
The main reported benefits of increased GABA levels are reduced anxiety and stress, along with greater overall well-being (3, 4). GABA may increase Growth Hormone secretion to promote the growth of lean muscle, fat-burning, and stabilization of blood pressure (5, 6).
GABA is naturally produced in the body, though plant-derived supplements are commonly available. Uptake into the brain is more efficient with low doses, and less efficient at higher concentrations (7). This is because GABA has the ability to tightly regulate itself: it blocks its own transport when too much is present ensuring neurological levels of GABA remain constant (8).
Supplemental GABA is not absorbed efficiently, but nitric oxide can be taken with GABA to increase absorption into the brain through the blood brain barrier (10). GABA is commonly used in nootropic supplements along with other ingredients such as l-theanine and bacopa, which work together to increase GABA synthesis in the brain to induce the desired effects of elevated mood, reduced stress, and anxiety (11).