L-Theanine
An amino acid found naturally in green tea that promotes calm focus by enhancing alpha brain waves. One of the most popular focus supplements, especially when combined with caffeine.
Known Health Benefits
Active Compounds
L-γ-glutamylethylamide
Dosage Guidance
100–400 mg daily (200 mg + 100 mg caffeine for focus)
Always consult a healthcare provider for personalized dosing.
Potential Side Effects
Generally very well tolerated; rare headache or drowsiness at high doses
Known Drug Interactions
May enhance effects of blood pressure medications and stimulants
Evidence Classification
Supported by cohort studies, case-control studies, or multiple observational studies with consistent findings.
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This entry is for educational purposes only. It is not medical advice. Always consult a qualified healthcare provider before starting, stopping, or changing any supplement regimen, especially if you take medications or have health conditions.