GABA (gamma-aminobutyric acid) is a non-protein amino acid that functions as a neurotransmitter (a chemical that facilitates communication between neurons). Neurotransmitters are either "excitatory" (i.e. they stimulate the firing of a neuron) or "inhibitory" (i.e., they tend to suppress neuron firing). GABA, which is produced from glutamate, is an inhibitory neurotransmitter. In fact, it's the primary inhibitory neurotransmitter in the brain.
Since GABA is a naturally-occurring, easily synthesized, physiologically-important compound, it's readily available in supplement form. It's also found in various functional food products.
Why is GABA so popular? It appears to reduce anxiety and promote a sense of calm. Herbalists often recommend GABA as an alternative to the herb kava for people who want a natural tranquilizer. The effects of GABA are mild and it does not cause sedation. GABA is also used to promote sleep.
GABA is available in tablets, capsules and in powdered form (not to mention Jones Soda.). Capsules can be opened and mixed with liquid to make them easier to ingest. Sublingual tablets of GABA (tablets that are placed under the tongue to dissolve) are also available.
Calcium diascorbate; Calcium L-ascorbate; Hemicalcium ascorbate; Calci-C; E302