Compound Monograph
Theanine
Theanine is an amino acid found almost uniquely in tea, associated with a calm, focused state without sedation.
Where Does It Come From? (2)
Theanine is a naturally occurring amino acid analogue (glutamine derivative), found in Tea and Some Boletus mushrooms. It is well tolerated orally (low toxicity).
Research & Evidence
Theanine (usually L-theanine) is a non-protein amino acid found almost exclusively in tea, where it contributes a savoury, umami quality and accounts for much of tea’s reputation for promoting calm alertness. It can cross into the brain and influences neurotransmitter systems and alpha brain-wave activity; human studies have explored its effects on relaxation, attention and stress, often in combination with caffeine, with which it is thought to smooth out the stimulant effect.
Toxicity & Safety
Theanine is well tolerated and regarded as low in toxicity, being a normal component of a widely consumed beverage. It is not notably sedating and has a good safety record in the doses used in research, though formal long-term data are limited.
Dosage
Research has commonly used oral doses in the region of roughly 175–300 mg, sometimes alongside caffeine. These figures describe doses studied in research and are not a recommendation.