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Theanine chemical structure

2-Amino-4-(ethylcarbamoyl)butyric acid
IUPAC name
CAS number
ATC code


Chemical formula {{{chemical_formula}}}
Molecular weight 174.20 g/mol
Bioavailability {{{bioavailability}}}
Elimination half-life {{{elimination_half-life}}}
Pregnancy category {{{pregnancy_category}}}
Legal status Legal everywhere
Routes of administration Oral

Theanine is an amino acid commonly found in tea (infusions of Camellia sinensis). Theanine is related to a glutamine, and can cross the blood-brain barrier.[1] Because it can enter the brain, theanine has psychoactive properties.[2] Theanine has been shown to reduce mental and physical stress[3] and may produce feelings of relaxation.[4]

Theanine is speculated to produce these effects by increasing the level of gamma-aminobutyric acid (GABA) production. Theanine increases brain serotonin, dopamine, GABA levels and has micromolar affinities for AMPA, Kainate and NMDA receptors.[5] It has also been found that injecting spontaneously hypertensive mice with theanine significantly lowered levels of 5-hydroxyindole in the brain.[6] Researchers also speculate that it may inhibit glutamic acid excitotoxicity.[5] Theanine also promotes alpha wave production in the brain.[2]

Studies on test rats have shown that even repeated, extremely high doses of theanine cause little to no harmful psychological or physical effects.[7]

L-theanine may help the body's immune response when fighting infection by boosting the disease-fighting capacity of gamma delta T cells. The study, released in 2003 by the Brigham and Women's Hospital, included a four-week trial with 11 coffee drinkers and 10 tea drinkers, who consumed 600 milliliters of coffee or black tea daily. Blood sample analysis found that the production of anti-bacterial proteins was up to five times higher in the tea-drinkers, an indicator of a stronger immune response.[8]

See alsoEdit


  1. Yokogoshi H, Kobayashi M, Mochizuki M, Terashima T (1998). Effect of theanine, r-glutamylethylamide, on brain monoamines and striatal dopamine release in conscious rats. Neurochem Res 23 (5): 667-73. PMID 9566605.
  2. 2.0 2.1 Gomez-Ramirez M. The Deployment of Intersensory Selective Attention: A High-density Electrical Mapping Study of the Effects of Theanine. Clin Neuropharmacol 30 (1): 25-38. PMID 17272967.
  3. Kimura K, Ozeki M, Juneja L, Ohira H (2007). L-Theanine reduces psychological and physiological stress responses. Biol Psychol 74 (1): 39-45. PMID 16930802.
  4. Lu K, Gray M, Oliver C, Liley D, Harrison B, Bartholomeusz C, Phan K, Nathan P (2004). The acute effects of L-theanine in comparison with alprazolam on anticipatory anxiety in humans. Hum Psychopharmacol 19 (7): 457-65. PMID 15378679.
  5. 5.0 5.1 Nathan P, Lu K, Gray M, Oliver C (2006). The neuropharmacology of L-theanine(N-ethyl-L-glutamine): a possible neuroprotective and cognitive enhancing agent. J Herb Pharmacother 6 (2): 21-30. PMID 17182482.
  6. Yokogoshi H, Kato Y, Sagesaka YM, Takihara-Matsuura T, Kakuda T, Takeuchi N (1995). Reduction effect of theanine on blood pressure and brain 5-hydroxyindoles in spontaneously hypertensive rats.. Biosci Biotechnol Biochem. 59 (4): 615-618. PMID 7539642.
  7. Borzelleca J, Peters D, Hall W (2006). A 13-week dietary toxicity and toxicokinetic study with L-theanine in rats. Food Chem Toxicol 44 (7): 1158-66. PMID 16759779.
  8. Kamath A, Wang L, Das H, Li L, Reinhold V, Bukowski J (2003). Antigens in tea-beverage prime human Vgamma 2Vdelta 2 T cells in vitro and in vivo for memory and nonmemory antibacterial cytokine responses. Proc Natl Acad Sci U S A 100 (10): 6009-14. PMID 12719524.

es:Teaninafi:Teaniini zh:茶氨酸

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