Glutamate

Non-essential amino acid and the most abundant excitatory neurotransmitter in the brain. Abundant in dietary protein. As a standalone supplement, evidence for specific health benefits is limited. Plays a role in nitrogen metabolism and serves as a precursor to GABA and glutathione (via glutamate-cysteine ligase). Present in many amino acid blends. Not to be confused with L-glutamine, which is a different amino acid. No established RDA/UL.