Approximate dose-response bands. Individual response varies — these are starting points, not prescriptions.
Well below target. Risk of deficiency symptoms tied to calm · focus.
Below the recommended daily target. Long-term adequacy not assured.
Daily target met. Standard nutritional support for calm · focus.
Common for specific health goals. Check the evidence for your situation before sustaining this level.
Past the point where extra intake typically helps. Evidence for further benefit is thin.
You're at 0% of your l-theanine target. The biggest single-serving sources to top it off:
Amino acid uniquely abundant in green and black tea. Crosses the blood-brain barrier and modulates GABA, glutamate, dopamine, and serotonin. Famous for producing 'alert calm' — used to take the edge off caffeine without sedation.
Structurally similar to glutamate; binds glutamatergic receptors with low affinity but doesn't trigger excitatory signalling — likely acting as a partial agonist that reduces overall glutamate tone. Increases brain alpha-wave power (8–13 Hz) within 30–40 minutes of oral dosing, an EEG signature of 'relaxed wakefulness'.
Not an essential nutrient — no deficiency state. The 'baseline' for theanine is whatever you get from tea consumption.
Well-tolerated to ~600 mg/day in trials. GRAS status in the US. No established UL.
Suntheanine is a patented, consistent L-theanine and the form used in most clinical trials. 100–200 mg is the typical dose. Pairs cleanly with caffeine in a 2:1 theanine:caffeine ratio (e.g. 200 mg theanine + 100 mg caffeine).
Rapidly absorbed; plasma peaks at ~50 minutes, brain uptake by 90 minutes. Crosses the blood-brain barrier via the leucine-preferring amino acid transporter. Half-life ~3 hours.
No direct longevity signal but the stress-reduction and sleep-quality effects are healthspan-relevant. Whole-tea consumption (containing theanine, polyphenols, modest caffeine) correlates with lower all-cause mortality in large cohorts.
Tea-derived amino acid; alpha-wave EEG activity, calm focus, attenuates caffeine jitters. Common dose 100–400 mg.
The mechanisms and systems this nutrient feeds. Click any to drill into what runs on it.