Cognition · Evidence Moderate
L-Theanine
An amino acid from tea leaves that pairs well with caffeine for calmer focus.
Dosage
100–200 mg
Timing
With caffeine, or in the evening for relaxation
Evidence
Moderate
Overview
L-theanine's most reliable use is pairing 1:2 with caffeine (e.g., 100 mg L-theanine with 200 mg caffeine) to reduce jitters and support steady focus.
Benefits
- →Smooths caffeine jitters
- →May support subjective calm focus
Best for
Stacks with
Side effects
- • Very well tolerated at typical doses
Warnings & cautions
- ⚠Consult a physician if you take blood-pressure or sedative medication.
Drug & condition interactions
- • May potentiate sedatives; may modestly lower blood pressure.
Evidence notes
Short-term trials show subjective reductions in stress markers and improved attention when combined with caffeine.
Research references
- [1] Owen GN et al. The combined effects of L-theanine and caffeine on cognitive performance and mood. — Nutr Neurosci, 2008; 11:193–198
Medical disclaimer
This page is for general educational purposes only and is not medical advice. Individual response to supplements varies. Consult a licensed healthcare provider before starting any supplement — especially if you are pregnant, breastfeeding, under 18, taking prescription medication, or managing a medical condition.