Cognitive & Focus

L-Theanine: Benefits, Dosage & What the Science Says

Amino acid from tea leaves associated with relaxation and alpha-wave activity without sedation.

Last reviewed: Moderate evidence
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Botanical field plate of green tea, the natural source of L-theanine
Botanical plate from NaturalHerbLibrary.com

Decision snapshot

What matters before you buy

Evidence
Moderate
Studied dose
100–400 mg/day; often 200 mg for acute calm-focus.
Quality marker
Look for a clearly disclosed form, useful dose and independent testing.
Safety check
Well-tolerated; limited interactions reported.

What Is L-Theanine?

Calm focus and relaxation without sedation

Evidence-Based Benefits

  • Relaxation without drowsiness
  • Focus enhancement
  • Sleep synergy with caffeine or GABA

Recommended Dosage

100–400 mg/day; often 200 mg for acute calm-focus.

Safety, Side Effects & Interactions

Well-tolerated; limited interactions reported.

Works Well With

Research suggests L-Theanine may complement:

Traditional Use

Traditional Chinese Medicine
绿茶 Lǜ Chá
clears heat promotes alertness benefits the mind resolves phlegm

View herb profile on NaturalHerbLibrary.com →

References

  1. Theanine and cognition - PMID:0001006

Last reviewed: April 20, 2026. For informational purposes only. See full disclaimer. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

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