L-Theanine
Amino acid from tea; promotes calm focus without drowsiness.
By Suplagen Team · Updated
What it is
L-Theanine is an amino acid found naturally in tea leaves. It promotes relaxation and alpha brain wave activity without sedation.
How it works
Increases alpha brain wave activity; modulates GABA, serotonin, and dopamine levels for calm alertness.
What the evidence says
Moderate evidence for promoting relaxed alertness; well-studied synergy with caffeine for focus.
How much to take
The catalog range is 100 to 400 mg daily, with 400 mg as the ceiling. The classic pairing, 100 to 200 mg with a normal caffeine dose, is where most of the evidence and most of the use sits.
L-theanine is very well tolerated across the range. Start at 100 mg; there's no reward for pushing to the ceiling.
When and how to take it
Morning with caffeine for focused calm, or evening on its own for relaxation. It works with or without food.
It's the calm-without-sedation option: in our sleep guide for racing-mind evenings, and compared with melatonin for which sleep problem it fits.
Who should skip it
No contraindicated conditions. One mild interaction: blood pressure medication, since L-theanine can nudge pressure down. Pregnancy safety isn't established. Otherwise it's one of the gentlest entries in the catalog.
Safety Notes
- Very well-tolerated. 100-200 mg with caffeine is a popular nootropic stack.
- blood pressure medications: May slightly lower blood pressure; monitor.
Timing With Other Supplements
- Caffeine: Synergistic pairing; L-theanine smooths caffeine's stimulatory edge.
Common questions
How much L-theanine should I take?
100 to 400 mg, with 100 to 200 mg being the well-studied dose alongside caffeine. The ceiling is 400 mg.
When should I take L-theanine?
Morning with coffee for focus, or evening for winding down. It has no food rules and no timing conflicts, so either slot works.
Does L-theanine make you sleepy?
No. It promotes relaxed alertness, which is why it pairs with caffeine. In the evening it helps you settle without sedating you; if you need a sedative effect, it's the wrong tool.