L-theanine

L-theanine is a naturally occurring, non-protein amino acid predominantly found in tea leaves (Camellia sinensis) and a few species of mushrooms, including Xerocomus badius[4][6]. Chemically, it is N5-ethyl-L-glutamine, an analog of glutamic acid and glutamine, and it exists in the L (S) chiral configuration in nature[1][2]. L-theanine contributes to the umami flavor of tea and is associated with several physiological effects: it facilitates relaxation, reduces stress, supports cognition, and can increase alpha brain wave activity[2][6][7]. Mechanistically, L-theanine is thought to modulate levels of certain neurotransmitters in the brain, including GABA, dopamine, and serotonin, and may antagonize glutamate receptors or transporters[2][6][8]. It does not function as a traditional drug target (i.e., receptor, enzyme, transporter), but acts as a bioactive dietary component and supplement. L-theanine is widely studied for its health-related effects and is regarded as safe for consumption in reasonably expected amounts from food and supplements[2][4][7].

Other names

theanineN5-ethyl-L-glutamineN-ethyl-L-glutamineγ-L-glutamylethylamideL-glutamic acid-gamma-ethylamideSuntheanine (trade name)