L-Theanine — Supplements
Green tea amino acid promoting relaxation without sedation via alpha brain wave modulation.
Overview
L-theanine is a non-proteinogenic amino acid found predominantly in tea leaves (Camellia sinensis) that promotes relaxation without sedation. It crosses the blood-brain barrier and increases alpha brain wave activity (associated with calm alertness), modulates GABA, serotonin, and dopamine neurotransmission, and attenuates the sympathomimetic effects of caffeine when co-administered. RCTs demonstrate significant improvements in attention, relaxation, sleep quality, and stress-induced anxiety. The caffeine + L-theanine combination is one of the most well-studied nootropic stacks.
Indications
- Stress and anxiety reduction (without sedation)
- Focused attention and cognitive performance
- Sleep quality improvement
- Caffeine synergy (enhanced focus, reduced jitteriness)
Mechanism of Action
Increases alpha brain wave activity (8-13 Hz), associated with relaxed alertness and creativity
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| L-Theanine | 200 mg | 1-2 times daily | Can combine with 100 mg caffeine for optimal focus; 200 mg at bedtime for sleep |
Evidence Grade
GRADE C
Safety & Contraindications
- Excellent safety profile; no significant adverse effects reported
- May potentiate blood pressure-lowering effects of antihypertensive medications
- Generally does not cause drowsiness at standard doses
- Safe for daily, long-term use based on available evidence