Neurologically-Active Amino Acid Promotes Relaxation Supports Learning Ability Suntheanine Dietary Supplement Non GMO Certified by NSF Suitable for Vegetarians/Vegans Theanine is a unique amino acid found almost exclusively in green tea that exerts beneficial effects on brain metabolism. Theanine induces relaxation without causing drowsiness, as measured by increased generation of alpha-waves. Theanine may improve learning ability and sensations of pleasure by affecting dopamine and serotonin neurotransmitters in the brain. Also, theanine exerts protective effects on the brain by mitigating glutamate toxicity. Jarrow Formulas Theanine is made enzymatically from amino acids and is identical to the theanine found in green tea.