sleep

L-Theanine Sleep Maintenance Randomized Trial Evidence Table

Structured evidence table for L-Theanine Sleep Maintenance Randomized Trial, generated from 2 reusable source documents in the Migaku knowledge base.

topicclaimevidence levelcitationsource
L-Theanine Sleep Maintenance Randomized TrialMatcha and green-tea bioactives are widely promoted for stress and hormonal health, yet the evidence is fragmented across chemically dissimilar preparations (whole-leaf matcha, brewed green tea, isolated L-theanine, and concentrated epigallocatechin-3-gallate, EGCG) that are routinely treated as interchangeable.1Alanazi A (2026)A CE/TA-stratified systematic review and evidence map of matcha and green tea bioactives in endocrine stress regulation: testosterone, cortisol, and the T:C ratio.
L-Theanine Sleep Maintenance Randomized TrialThis review adopts that index and applies it, for the first time, as a stratification variable across a formally assembled endocrine evidence base, in order to map what is and is not established regarding cortisol, testosterone, and the testosterone-to-cortisol (T:C) ratio.1Alanazi A (2026)A CE/TA-stratified systematic review and evidence map of matcha and green tea bioactives in endocrine stress regulation: testosterone, cortisol, and the T:C ratio.
L-Theanine Sleep Maintenance Randomized TrialFollowing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement and its search extension (PRISMA-S), seven electronic sources were searched from inception to March 31, 2026, and findings were synthesized using the Synthesis Without Meta-analysis (SWiM) guideline because the studies were not sufficiently comparable for meta-analysis.1Alanazi A (2026)A CE/TA-stratified systematic review and evidence map of matcha and green tea bioactives in endocrine stress regulation: testosterone, cortisol, and the T:C ratio.
L-Theanine Sleep Maintenance Randomized TrialA compositional index for this problem already exists: the caffeine-plus-EGCG-to-L-theanine-plus-arginine (CE/TA) molar ratio, developed by Unno and colleagues for matcha and Japanese green-tea preparations, together with an indicative screening threshold.1Alanazi A (2026)A CE/TA-stratified systematic review and evidence map of matcha and green tea bioactives in endocrine stress regulation: testosterone, cortisol, and the T:C ratio.
L-Theanine Sleep Maintenance Randomized TrialCamellia sinensis 1 2 3 4 5 L-theanine is a naturally occurring, water-soluble, non-proteinogenic amino acid that can be found in the tea plantand some mushrooms ().3Cotter Jack (2026)Effects of L-theanine on cognition, mood and sleep: evidence from human trials
L-Theanine Sleep Maintenance Randomized TrialIn addition, we examine evidence relating to its safety, consider the limitations of the current literature and highlight key areas for future research.3Cotter Jack (2026)Effects of L-theanine on cognition, mood and sleep: evidence from human trials
L-Theanine Sleep Maintenance Randomized Trial13 14 13 14 Table 1 13 15 16 17 18 19 There is growing interest among consumers for products that can help to support aspects of cognitive performance, such as attention, decision-making and memory, as well as associated subjective measures like perceived alertness and mental fatigue.3Cotter Jack (2026)Effects of L-theanine on cognition, mood and sleep: evidence from human trials
L-Theanine Sleep Maintenance Randomized TrialIt constitutes up to 50% of the total amino acids in tea and accounts for approximately 1–2% of its dry weight, contributing to tea's characteristic umami flavor (,).3Cotter Jack (2026)Effects of L-theanine on cognition, mood and sleep: evidence from human trials
topicL-Theanine Sleep Maintenance Randomized Trial
claimMatcha and green-tea bioactives are widely promoted for stress and hormonal health, yet the evidence is fragmented across chemically dissimilar preparations (whole-leaf matcha, brewed green tea, isolated L-theanine, and concentrated epigallocatechin-3-gallate, EGCG) that are routinely treated as interchangeable.
evidence level1
citationAlanazi A (2026)
sourceA CE/TA-stratified systematic review and evidence map of matcha and green tea bioactives in endocrine stress regulation: testosterone, cortisol, and the T:C ratio.
topicL-Theanine Sleep Maintenance Randomized Trial
claimThis review adopts that index and applies it, for the first time, as a stratification variable across a formally assembled endocrine evidence base, in order to map what is and is not established regarding cortisol, testosterone, and the testosterone-to-cortisol (T:C) ratio.
evidence level1
citationAlanazi A (2026)
sourceA CE/TA-stratified systematic review and evidence map of matcha and green tea bioactives in endocrine stress regulation: testosterone, cortisol, and the T:C ratio.
topicL-Theanine Sleep Maintenance Randomized Trial
claimFollowing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement and its search extension (PRISMA-S), seven electronic sources were searched from inception to March 31, 2026, and findings were synthesized using the Synthesis Without Meta-analysis (SWiM) guideline because the studies were not sufficiently comparable for meta-analysis.
evidence level1
citationAlanazi A (2026)
sourceA CE/TA-stratified systematic review and evidence map of matcha and green tea bioactives in endocrine stress regulation: testosterone, cortisol, and the T:C ratio.
topicL-Theanine Sleep Maintenance Randomized Trial
claimA compositional index for this problem already exists: the caffeine-plus-EGCG-to-L-theanine-plus-arginine (CE/TA) molar ratio, developed by Unno and colleagues for matcha and Japanese green-tea preparations, together with an indicative screening threshold.
evidence level1
citationAlanazi A (2026)
sourceA CE/TA-stratified systematic review and evidence map of matcha and green tea bioactives in endocrine stress regulation: testosterone, cortisol, and the T:C ratio.
topicL-Theanine Sleep Maintenance Randomized Trial
claimCamellia sinensis 1 2 3 4 5 L-theanine is a naturally occurring, water-soluble, non-proteinogenic amino acid that can be found in the tea plantand some mushrooms ().
evidence level3
citationCotter Jack (2026)
sourceEffects of L-theanine on cognition, mood and sleep: evidence from human trials
topicL-Theanine Sleep Maintenance Randomized Trial
claimIn addition, we examine evidence relating to its safety, consider the limitations of the current literature and highlight key areas for future research.
evidence level3
citationCotter Jack (2026)
sourceEffects of L-theanine on cognition, mood and sleep: evidence from human trials
topicL-Theanine Sleep Maintenance Randomized Trial
claim13 14 13 14 Table 1 13 15 16 17 18 19 There is growing interest among consumers for products that can help to support aspects of cognitive performance, such as attention, decision-making and memory, as well as associated subjective measures like perceived alertness and mental fatigue.
evidence level3
citationCotter Jack (2026)
sourceEffects of L-theanine on cognition, mood and sleep: evidence from human trials
topicL-Theanine Sleep Maintenance Randomized Trial
claimIt constitutes up to 50% of the total amino acids in tea and accounts for approximately 1–2% of its dry weight, contributing to tea's characteristic umami flavor (,).
evidence level3
citationCotter Jack (2026)
sourceEffects of L-theanine on cognition, mood and sleep: evidence from human trials

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Source documents

  1. A CE/TA-stratified systematic review and evidence map of matcha and green tea bioactives in endocrine stress regulation: testosterone, cortisol, and the T:C ratio.
  2. Effects of L-theanine on cognition, mood and sleep: evidence from human trials