🇺🇸 FDA
GRAS (Suntheanine GRN 209) · DSHEA dietary supplement
L-Theanine (γ-glutamylethylamide · tea-derived amino acid)
Also known as: Theanine · γ-Glutamylethylamide · Suntheanine (registered)
Mechanism of action
- α-wave EEG activity promotion (relaxed alertness)
- Glutamate receptor partial antagonism
- GABA + dopamine + serotonin modulation
- Caffeine synergy (smoothed stimulation curve)
Molecular + tissue targets
- CNS GABAergic + glutamatergic systems
- Stress-axis (HPA)
- Cognitive arousal
Dosage range
100-400 mg/day; 200 mg most common acute-stress RCT dose; 200 mg + 100 mg caffeine for attention/focus
Safety notes
Generally well tolerated (GRAS in tea food matrix); no notable interactions; pregnancy data limited
Cross-market regulatory status
🇪🇺 EFSA
Authorized as food supplement; no health claim
🇧🇷 ANVISA
RDC 243/2018 dietary supplement · IN 28/2018 alegação funcional not specifically authorized
Common use cases
- stress reduction (research context)
- sleep quality support
- attention/focus (caffeine co-supplementation)
Cross-reference
Health goals: cognitive support inflammation relief
Lifestyles: high stress high stress high stress
Full dossier: /ingredients/l-theanine/
Machine-readable JSON: /api/nc/l-theanine.json