ArticlePharmaceutical biology2019
GABA and l-theanine mixture decreases sleep latency and improves NREM sleep.
Article in Pharmaceutical biology, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to 2 registered trials, which are not on this map. Cited by 75 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
A Double-blind, Randomized, Placebo-controlled Study to Evaluate the Effects of a Theanine Formulation on Stress, Burnout, Mood, and Sleep in Individuals Who Report Occasional Moderate or High Levels of Stress
A Double-blind, Randomized, Placebo-controlled Study to Evaluate the Effects of a Theanine for Stress Relief Formulation on Stress, Burnout Component, Mood, and Sleep in Individuals Who Report Occasional Moderate or High Levels of Stress
Who cites it
75 citing papers in PubMed, 2 syntheses or guidelines pooled it, 149 citations in OpenAlex.
- Dietary Supplement Interventions and Sleep Quality Improvement: A Systematic Review and Meta-Analysis.Nutrients · 2025Pooled it
- Nutritional interventions in treating menopause-related sleep disturbances: a systematic review.Nutrition reviews · 2024Pooled it
- Trial
- Effects of Bifidobacterium breve 207-1 on regulating lifestyle behaviors and mental wellness in healthy adults based on the microbiome-gut-brain axis: a randomized, double-blind, placebo-controlled trial.European journal of nutrition · 2024Trial
- Trial
- Effects of Matcha Green Tea Powder on Cognitive Functions of Community-Dwelling Elderly Individuals.Nutrients · 2020Trial
- Review
- Exploring the Physiological Effects and Mechanisms of Gamma-Aminobutyric Acid in Food Systems.Foods (Basel, Switzerland) · 2026Review
- Faecalibacterium prausnitzii-derived L-arginine ameliorates insomnia by inhibiting POMC-ACTH-cortisol axis.Cell reports. Medicine · 2026Article
- The sleep-wake cycle: molecular mechanisms, disorders, and therapeutic targets in the context of energy metabolism.Signal transduction and targeted therapy · 2026Review
- Combined Administration of Cannabidiol and L-Theanine Improves Sleep-Related Outcomes in Caffeine-Induced Sleep Disturbances Mouse Model.Biomolecules & therapeutics · 2026Article
- Role of gamma-aminobutyric acid-ergic neurons in the thalamic reticular nucleus in regulating sleep-wake cycles in mice treated with acupuncture for insomnia.Journal of traditional Chinese medicine = Chung i tsa chih ying wen pan · 2026Article
- Dietary Protocols to Promote and Improve Restful Sleep: A Narrative Review.Nutrition reviews · 2026Review
- Phytochemical and Fungal Bioactive Compounds in the "Brain Health Triad": A Narrative Review on Neurostimulating, Neurotrophic, and Neuroprotective Synergy.International journal of molecular sciences · 2026Review
- Process Optimization of GABA Instant White Tea Based on Response Surface Methodology and Analysis of Key Flavor Substances.Foods (Basel, Switzerland) · 2026Article
- Time-Dynamic analysis of sex-specific NREM sleep disturbance induced by social isolation among adolescent mice.Translational psychiatry · 2026Article
- Effects of L-theanine on cognition, mood and sleep: evidence from human trials.Frontiers in nutrition · 2026Review
- Network Pharmacology-Based Elucidation of Gu's Anshen Decoction in Modulating TNF Signaling to Ameliorate Insomnia.Nature and science of sleep · 2026Article
- Causal relations of trace elements and nutrients with insomnia: A Mendelian randomization study.Medicine · 2025Article
- Progress in Research on the Mechanism of GABA in Improving Sleep.Foods (Basel, Switzerland) · 2025Review
15 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors at 2 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
contextγ-Aminobutyric acid (GABA) is the main inhibitory neurotransmitter and it is well established that activation of GABA
objectiveThis study investigated the potential synergistic sleep enhancement effect of GABA/l-theanine mixture. MATERIALS AND
methodsPentobarbital-induced sleep test was applied to find proper concentration for sleep-promoting effect in ICR mice. Electroencephalogram (EEG) analysis was performed to investigate total sleeping time and sleep quality in normal SD rats and caffeine-induced awareness model. Real-time polymerase chain reaction (RT-PCR) was applied to investigate whether the sleep-promoting mechanism of GABA/l-theanine mixture involved transcriptional processes.
resultsGABA/l-theanine mixture (100/20 mg/kg) showed a decrease in sleep latency (20.7 and 14.9%) and an increase in sleep duration (87.3 and 26.8%) compared to GABA or theanine alone. GABA/l-theanine mixture led to a significant increase in rapid eye movement (REM) (99.6%) and non-REM (NREM) (20.6%) compared to controls. The use of GABA/l-theanine mixture rather than GABA or l-theanine alone restored to normal levels sleep time and quality in the arousal animal model. The administration of GABA/l-theanine led to increased expression of GABA and the glutamate GluN1 receptor subunit.
conclusionsGABA/l-theanine mixture has a positive synergistic effect on sleep quality and duration as compared to the GABA or l-theanine alone. The increase in GABA receptor and GluN1 expression is attributed to the potential neuromodulatory properties of GABA/l-theanine combination, which seems to affect sleep behaviour.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.