L-Theanine is a relaxing, health-promoting amino acid found in green tea leaves in which it constitutes 1-2% of dry weight, also conferring the characteristic umami flavor. L-Theanine increases alpha-waves producing mental and physical relaxation, decreasing stress and anxiety, without inducing drowsiness while possibly increasing attention. Possible mechanism links with the release of neurotransmitters (GABA and, in turn, serotonin and dopamine).