L-Theanine
Non-proteinogenic amino acid structurally analogous to glutamate. Crosses the blood-brain barrier via the leucine-preferring transport system. Increases alpha-wave activity (8-13 Hz) within 30-45 minutes, producing relaxed alertness without sedation. Modulates glutamate, GABA, serotonin, and dopamine levels in the prefrontal cortex and hippocampus. Inhibits cortical neuron excitotoxicity by blocking glutamate binding at AMPA, kainate, and NMDA receptors at high concentrations.
Three tiers ordered by aggressiveness. Tier chips on every OPTIMIZE intervention let you filter the catalog by your evidence tolerance.
- hypotension-severe
- PMID:18296328L-Theanine, a natural constituent in tea, and its effect on mental state — Asia Pac J Clin Nutr, 2008
- PMID:18681988The acute effects of L-theanine in comparison with alprazolam on anticipatory anxiety in humans — Hum Psychopharmacol, 2004
- PMID:21040626Effects of L-theanine on attention and reaction time response — J Funct Foods, 2011
L-Theanine is the rare compound where the mechanism is simple, the evidence is clean, and the practical application is obvious. 100-200mg with caffeine produces focused attention without jitter. Alpha-wave induction within 40 minutes. No tolerance. No dependence. No withdrawal. The caffeine-theanine stack is probably the single most validated nootropic combination in existence. 2-to-1 theanine-to-caffeine ratio. The fact that green tea figured this out 5,000 years ago should tell you something about the reliability of evolutionary pharmacology.
This is not medical advice
Discuss with a licensed clinician before starting, stopping, or changing any compound. This page documents what the research literature describes — it is not a prescription.
See L-Theanine in a protocol matched to you