L-Theanine
Calm focus without sedation — smooths caffeine and takes the edge off stress.
- Typical dose
- 100–200 mg
- When to take
- Anytime
- Onset
- 30–60 minutes after a dose
What it does
Benefits
- Promotes calm, focused alertness
- Reduces the jittery edge of caffeine
- Supports sleep onset when taken in the evening
- May lower stress-induced blood pressure
The science
How it works
An amino acid from tea that increases alpha brain wave activity and modulates glutamate, GABA, and dopamine — producing relaxed alertness rather than drowsiness.
Getting it right
Dose & timing
Dose guidance
100–200 mg per dose. Up to 400 mg/day is well-tolerated. 2:1 theanine-to-caffeine ratio is the classic pairing.
Best time to take
Morning with coffee for focus; evening for wind-down. Anytime stress hits.
Is it for you?
Who should (and shouldn't) take it
Good for
- Caffeine-sensitive people
- High-stress workdays
- Racing mind at bedtime
- Social anxiety situations
Skip or ask a doctor if
- You take blood pressure medications (may enhance effect)
- You are on stimulants for ADHD (talk to your doctor)
Know before you start
Side effects & safety
- Rare — mild headache at high doses
- Very mild drowsiness in sensitive users
Shopping guide
Forms & what to look for
- Capsule
Most convenient; precise dose
- Suntheanine
Patented, pure L-isomer — evidence-backed
- Powder
Flexible but bitter
Combining
Stacks well with / avoid pairing
Common questions
FAQ
How is this different from the caffeine + theanine combo?
Same ingredient — standalone lets you dose it separately from caffeine, or use it in the evening.
Will it make me sleepy?
Not at typical doses. It produces calm, not sedation.
References
Sources & further reading
Educational only, not medical advice. Check with a clinician before starting anything new, especially if you're on medication or pregnant.