L-Theanine Research Reference

Catalog classification, reference sizes, lab math links, and source-backed data. Educational use only — not medical advice.

Researched for: L-Theanine evidence and protocol review

Amino Acids & Nutrients amino-acid PowderCapsule verified

Also known as: Theanine

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Quick Facts

Reference Sizes

1 g, 10 g

Storage

No approved consumer storage standard exists for this presentation; follow the lot-specific COA and validated stability data

Solubility

Water-soluble

Catalog Description

L-theanine is a non-protein amino acid found primarily in tea (Camellia sinensis). It is commonly studied for relaxation-without-sedation effects, often in combination with caffeine for attention-related outcomes; proposed mechanisms include modulation of alpha brain-wave activity and glutamate receptor interactions.

Catalog descriptions reflect research context only. Not a medical claim or treatment recommendation.

Research Profile

Half-Life

~1 hour (reported in some pharmacokinetic studies)

Onset

Subjective effects reported within an hour of oral dosing

Administration Routes (Research)

Oral

Reported Research Effects

Associated with calm-alertness / relaxation without sedation
Often studied in combination with caffeine for attention outcomes

Reported Research Side Effects

Human safety, pharmacokinetics, and interaction data are incomplete

Data source: Primary literature, regulator records, trial registries, and identity-specific evidence search

Reflects preclinical/research literature context only. Not a medical claim, dosing instruction, or treatment recommendation.

Research Protocols Reported in the Literature

200 mg single dose [Oral; Single dose; Before testing]Source: randomized acute-stress study
200 mg/day [Oral; 4 weeks; Daily]Source: randomized crossover stress/sleep study

Research Notes

Effects are outcome-specific and often modest; the 2026 meta-analysis identified heterogeneity and risk-of-bias limitations. The malformed 500 mg ceiling was removed.

Supplementary research context only. Not medical advice or a treatment recommendation.

Sources

L-theanine stress-related symptoms randomized trial — PubMed (NIH)
https://pubmed.ncbi.nlm.nih.gov/31623400/

Single-dose L-theanine stress trial — PubMed (NIH)
https://pubmed.ncbi.nlm.nih.gov/34562208/

L-theanine 2026 systematic review and meta-analysis — PubMed (NIH)
https://pubmed.ncbi.nlm.nih.gov/42410082/

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Research Use Only. All content is for educational and research reference only. Not medical advice, a treatment recommendation, or guidance on human use. Compounds are not FDA-approved drugs unless specifically noted.