Back to Sleep
Sleep

L-Theanine for SleepEvidence & Dosage

Alpha waves, isolated without caffeine for sleep use.

Studies last updated

Evidence at a glance

Total studies
139
With abstract
49
Meta / Systematic / RCT
38
Highly cited
50
Publication years
1971–2026

L-Theanine for Sleep in the context of Sleep

This topic is part of our "Sleep" world. There you'll find methodology, evidence and the highest-impact levers — plus the order in which they sensibly build on each other.

Go to Sleep

Top studies on L-Theanine for Sleep

Ranked by influential-citation count and publication year.

  1. Therapeutic potential of natural molecules against Alzheimer's disease via SIRT1 modulation.

    Biomed Pharmacother2023Review74 influential citations

    Alzheimer's disease (AD) is a neurodegenerative disease mainly characterized by progressive cognitive dysfunction and memory impairment. Recent studies have shown that regulating silent information regulator 1 (SIRT1) expression has a…

  2. Recent advances in the utilization of tea active ingredients to regulate sleep through neuroendocrine pathway, immune system and intestinal microbiota.

    Crit Rev Food Sci Nutr2023Review71 influential citations

    Sleep disorders have received widespread attention nowadays, which have been promoted by the accelerated pace of life, unhealthy diets and lack of exercise in modern society. The chemical medications to improve sleep has shown serious side…

  3. L-theanine, unique amino acid of tea, and its metabolism, health effects, and safety.

    Crit Rev Food Sci Nutr2017Review68 influential citations

    Tea has been a very popular beverage around the world for centuries. The reason that it is delicious, enabling hydration, showing warming and relaxing effect can be mentioned why it is consumed so much in addition to its prominent health…

  4. Medicinal herbs for the treatment of anxiety: A systematic review and network meta-analysis.

    Pharmacol Res2022n=29meta64 influential citations

    BACKGROUND: Anxiety disorder is a common psychiatric illness. Medicinal herbs have become a field of interest in the treatment of anxiety. This study aimed to evaluate and compare the efficacy and acceptability of all possible medicinal…

  5. Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial.

    Nutrients2019n=30RCT61 influential citations

    This randomized, placebo-controlled, crossover, and double-blind trial aimed to examine the possible effects of four weeks L-theanine administration on stress-related symptoms and cognitive functions in healthy adults. Participants were 30…

  6. Herbal and Natural Supplements for Improving Sleep: A Literature Review.

    Psychiatry Investig2024n=184other55 influential citations

    OBJECTIVE: Herbal and natural supplements have gained popularity as alternative treatments to insomnia and sleep disorders due to their perceived safety and potential effectiveness. This literature review summarizes the current evidence on…

  7. Effect of matcha green tea on cognitive functions and sleep quality in older adults with cognitive decline: A randomized controlled study over 12 months.

    PLoS One2024n=99rct46 influential citations

    OBJECTIVE: Lifestyle habits after middle age significantly impact the maintenance of cognitive function in older adults. Nutritional intake is closely related to lifestyle habits; therefore, nutrition is a pivotal factor in the prevention…

  8. Nutritional Modulation of Sleep Latency, Duration, and Efficiency: A Randomized, Repeated-Measures, Double-Blind Deception Study.

    Med Sci Sports Exerc2023n=16rct43 influential citations

    PURPOSE: This study aimed to test the hypothesis that a novel nutritional blend composed of tryptophan, glycine, magnesium, tart cherry powder, and l -theanine enhances subjective and objective measures of sleep during free living…

  9. Uncovering the effects and mechanisms of tea and its components on depression, anxiety, and sleep disorders: A comprehensive review.

    Food Res Int2024review40 influential citations

    Depression, anxiety and sleep disorders are prevalent psychiatric conditions worldwide, significantly impacting the physical and mental well-being of individuals. The treatment of these conditions poses various challenges, including…

  10. A comprehensive review on bioavailability, safety and antidepressant potential of natural bioactive components from tea.

    Food Res Int2022Review38 influential citations

    Depression is a global public health issue with high morbidity and mortality, which tends to cause fatigue, inability to concentrate, insomnia, and loss of appetite, especially represented by major depressive disorder (MDD).…

Frequently asked

What dosage was studied?
• Tea active ingredients (L-theanine, caffeine, tea polyphenols, tea pigments, tea polysaccharides, GABA) (not reported)
Which population does the evidence apply to?
Most studies investigated: unknown.
Are there safety considerations for L-Theanine for Sleep?
• Not reported in the abstract. • Acceptability included discontinuation due to adverse events. • The abstract does not specify which adverse events occurred. • Not reported

More topics in Sleep

Glycine

Glycine, sleep quality, body temperature and safety.

Alcohol & Sleep

Faster sleep onset, but REM suppression and night-time waking.

Antihistamines

Diphenhydramine, doxylamine — sleep fragmentation, anticholinergic dementia risks.

Apigenin

Chamomile, GABA modulation, and sleep quality.

Apigenin (Sleep)

A flavonoid from chamomile, GABA modulation, sleep quality.

Ashwagandha (Sleep)

Cortisol lowering, sleep quality — KSM-66 and Sensoril extracts.

Bedroom Darkness

Blackout curtains, sleep mask — melatonin and sleep depth.

Bedroom Temperature

Optimal 17–19°C — a falling core body temperature promotes sleep.

Benzodiazepines

Sedative/hypnotic — dependence, cognitive risks in older age.

Blue Light Filter

f.lux, Night Shift, glasses — the evidence and the marketing hype.

Bruxism

Teeth grinding — stress, night guard, trigger factors.

Caffeine Timing

Half-life ~5–6h — cut off 8–10h before sleep.

CBD for Sleep

Endocannabinoid system, REM effects, and dosage spectrum.

CBT-I

Cognitive behavioral therapy for insomnia — first-line therapy per the guidelines.

Circadian Rhythm

The internal ~24h clock — light as the main signal, peripheral clocks in the organs.

CPAP

Continuous positive airway pressure — the standard for moderate apnea.

Deep Sleep

N3 slow-wave sleep — physical recovery, GH release.

GABA Supplements

Blood-brain barrier, fermented GABA, and efficacy data.

Glycine for Sleep

Deep sleep, lowering body temperature, and 3 g in the evening.

Glycine (Sleep)

3g before bed — lowers core body temperature, modulates deep sleep.

Related topics from other worlds

Vitamins & Minerals

Kidneys & Hydration

GFR, electrolytes, hydration, over-/underhydration, acid-base balance.

Vitamins & Minerals

NAD+ Precursors

NMN, NR, NAD+, aging biology and evidence landscape.

Vitamins & Minerals

Quercetin

Allergies, senolytic properties, bioflavonoids and combination with bromelain.

Vitamins & Minerals

Vitamin B Complex

Methylation, B12, methylfolate, energy, and neurotransmitter synthesis.

Vitamins & Minerals

When to See a Doctor

Red flags: persistent pain, sudden changes, a mental health crisis.

Diagnostics & Biomarkers

Cycle Tracking

Menstrual cycle, symptoms, fertility — apps and wearables.