L-Theanine para Insônia
A Evidências Vários grandes ensaios clínicos mostram de forma consistente benefícios significativos.Baseado em 16 estudos (4 meta-analyses, 4 RCTs) com 916 participantes no total. 11/16 estudos mostram efeitos positivos.
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A
Conclusão
L-theanine is well-supported by research as a supplement that may help improve sleep quality, especially for people who struggle with a busy mind at bedtime.
- 11 out of 16 studies show positive effects, including 4 RCTs and 4 meta-analyses
- A 2026 systematic review confirmed L-theanine's benefits for sleep
- Shown to be comparable to melatonin for sleep improvement in a 2024 cancer patient trial
- Works by enhancing GABA activity and reducing mental arousal without next-day grogginess
Key Study Findings
systematic review
n=550
Double-blind
Examining the effect of L-theanine on sleep: a systematic review of dietary supplementation trials.
Dose: L-theanine 50-900 mg/day; effective range 200-450 mg/day
vs: Placebo
Efeito: Beneficial effects on sleep latency, maintenance, efficiency; improved perceived sleep satisfaction
None
RCT
n=120
2 weeks
Double-blind
Comparison Between Efficacy of Oral Melatonin and Oral L-theanine in Improving Sleep in Cancer Patients …
Dose: Melatonin 3 mg or L-theanine 200 mg taken 2h before bedtime for 14 days
vs: Placebo
Efeito: None
p<0.005
narrative review
Herbal and Natural Supplements for Improving Sleep: A Literature Review.
Dose: varies by supplement
vs: Placebo
Efeito: None
None
RCT
n=40
8 weeks
Double-blind
Dietary supplementation with Lactium and L-theanine alleviates sleep disturbance in adults: a double-blind, randomized, placebo-controlled …
Dose: None
vs: Placebo
Efeito: None
None
animal study (preclinical)
Protective effects of a probiotic-fermented germinated grain complex on neurotransmitters and sleep quality in sleep-deprived …
Dose: 7 L fermentation product; GABA 12.555 µmol/L, L-theanine 0.471 mg/mL
vs: Placebo
Efeito: None
p < 0.0001 (sleep duration KEY
systematic_review
The Role of Supplements and Over-the-Counter Products to Improve Sleep in Children: A Systematic Review.
Dose: iron, 5-hydroxytryptophan (5-HTP), theanine, antihistamines (OTC supplements)
vs: Placebo
Efeito: None
None
Key Statistics
16
Estudos
916
Participantes
↑
Positive
A
Nota
Referenced Papers
Examining the effect of L-theanine on sleep: a systematic review of dietary supplementation trials.
Systematic Review
Nutritional neuroscience
2026
Psychiatry investigation
2024
24 citações
Frontiers in microbiology
2024
13 citações
Frontiers in nutrition
2024
5 citações
Indian journal of …
2024
3 citações
The Role of Supplements and Over-the-Counter Products to Improve Sleep in Children: A Systematic Review.
Systematic Review
International journal of …
2023
14 citações
Nutrients
2023
6 citações
Child and adolescent …
2023
5 citações
Medicinal herbs for the treatment of anxiety: A systematic review and network meta-analysis.
Meta-Analysis
Pharmacological research
2022
51 citações
Food research international …
2022
46 citações
Pharmaceutical biology
2019
134 citações
Journal of psychiatric …
2019
46 citações
Paediatric drugs
2017
26 citações
To sleep or not to sleep: a systematic review of the literature of pharmacological treatments of insomnia in children and …
Systematic Review
Journal of child …
2013
56 citações
Pharmacology, biochemistry, and …
2012
51 citações
Medical science monitor …
2009
85 citações
Dosage & Usage
mg = milligrams · mcg = micrograms (1,000× smaller) · IU = International Units
Dosagens Comumente Utilizadas
- sleep:
- 200-400 mg, 30-60 min before bed
Limite superior: Not established; generally safe up to 900 mg/day
Dosagens Estudadas em Pesquisas
| Dosagem | Duração | Efeito | N |
|---|---|---|---|
| L-theanine 50-900 mg/day; effective range 200-450 mg/day | -- | Positive | 550 |
| Melatonin 3 mg or L-theanine 200 mg taken 2h before bedtime for 14 days | 2 weeks | Positive | 120 |
| varies by supplement | -- | Positive | -- |
| None | 8 weeks | Positive | 40 |
| 7 L fermentation product; GABA 12.555 µmol/L, L-theanine 0.471 mg/mL | -- | Positive | -- |
| iron, 5-hydroxytryptophan (5-HTP), theanine, antihistamines (OTC supplements) | -- | Mixed | -- |
| l-theanine 200 mg/day, GABA 111.1 mg/day, AVLE 50 mg/day, l-serine 300 mg/day | -- | Positive | 160 |
| None | -- | Positive | -- |
Melhor horário: 30-60 minutes before bed
Safety & Side Effects
Efeitos Colaterais Relatados
- ⚠ Headache
- ⚠ Dizziness
- ⚠ GI discomfort
Interações Conhecidas
- ● Blood pressure medications — L-theanine may lower blood pressure
- ● Stimulants (caffeine) — may partially counteract stimulant effects
- ● Sedatives — potential additive calming effects
Ingestão máxima tolerável: Not established; generally safe up to 900 mg/day
Consulte sempre o seu profissional de saúde antes de iniciar qualquer suplemento.Sempre consulte seu profissional de saúde antes de iniciar qualquer suplemento.
Frequently Asked Questions
Does L-Theanine help with Insônia?
Based on 16 studies with 916 participants, there is strong evidence from multiple clinical trials that L-Theanine may support Insônia management. Our evidence grade is A (Strong Evidence).
How much L-Theanine should I take for Insônia?
Studies have used various dosages. A commonly studied range is 200-400 mg, 30-60 min before bed. Always consult your healthcare provider before starting any supplement regimen.
Are there side effects of L-Theanine?
Reported side effects may include Headache, Dizziness, GI discomfort. Most side effects are mild and dose-dependent. Consult your doctor if you experience any adverse reactions.
How strong is the evidence for L-Theanine and Insônia?
We rate the evidence as Grade A (Strong Evidence). This rating is based on 16 peer-reviewed studies with 916 total participants. The overall direction of effect is positive.
Related Evidence
Outros ingredientes para Insônia
L-Theanine para outras condições
References
- [1] Jack Cotter et al.. Nutr Neurosci. 2026. Examining the effect of L-theanine on sleep: a systematic review of dietary supplementation trials. doi:10.1080/1028415X.2025.2556925 PubMed
- [2] Ji Won Yeom et al.. Psychiatry Investig. 2024. Herbal and Natural Supplements for Improving Sleep: A Literature Review. doi:10.30773/pi.2024.0121 PubMed
- [3] Jiahua Cheng et al.. Front Microbiol. 2024. Protective effects of a probiotic-fermented germinated grain complex on neurotransmitters and sleep quality in sleep-deprived mice. doi:10.3389/fmicb.2024.1438928 PubMed
- [4] Su Eun Lim et al.. Front Nutr. 2024. Dietary supplementation with Lactium and L-theanine alleviates sleep disturbance in adults: a double-blind, randomized, placebo-controlled clinical study. doi:10.3389/fnut.2024.1419978 PubMed
- [5] Madhuri S Kurdi et al.. Indian J Palliat Care. 2024. Comparison Between Efficacy of Oral Melatonin and Oral L-theanine in Improving Sleep in Cancer Patients Suffering From Insomnia: A Randomised … doi:10.25259/IJPC_89_2023 PubMed
- [6] Alice Innocenti et al.. Int J Mol Sci. 2023. The Role of Supplements and Over-the-Counter Products to Improve Sleep in Children: A Systematic Review. doi:10.3390/ijms24097821 PubMed
- [7] Fuminori Imafuku et al.. Nutrients. 2023. Analysis of the Effects of Known Sleep-Support Supplements in Relation to Life Habits, Sleep Conditions, and Sleep Problems. doi:10.3390/nu15102377 PubMed
- [8] Swapna N Deshpande et al.. Child Adolesc Psychiatr Clin N Am. 2023. Complementary and Integrative Approaches to Sleep Disorders in Children. doi:10.1016/j.chc.2022.08.008 PubMed
- [9] Wenting Zhang et al.. Pharmacol Res. 2022. Medicinal herbs for the treatment of anxiety: A systematic review and network meta-analysis. doi:10.1016/j.phrs.2022.106204 PubMed
- [10] Jie Shao et al.. Food Res Int. 2022. A comprehensive review on bioavailability, safety and antidepressant potential of natural bioactive components from tea. doi:10.1016/j.foodres.2022.111540 PubMed
- [11] Suhyeon Kim et al.. Pharm Biol. 2019. GABA and l-theanine mixture decreases sleep latency and improves NREM sleep. doi:10.1080/13880209.2018.1557698 PubMed
- [12] Jerome Sarris et al.. J Psychiatr Res. 2019. L-theanine in the adjunctive treatment of generalized anxiety disorder: A double-blind, randomised, placebo-controlled trial. doi:10.1016/j.jpsychires.2018.12.014 PubMed
- [13] Shweta Anand et al.. Paediatr Drugs. 2017. Safety, Tolerability and Efficacy of Drugs for Treating Behavioural Insomnia in Children with Attention-Deficit/Hyperactivity Disorder: A Systematic Review with Methodological … doi:10.1007/s40272-017-0224-6 PubMed
- [14] Jessica R Barrett et al.. J Child Adolesc Psychopharmacol. 2013. To sleep or not to sleep: a systematic review of the literature of pharmacological treatments of insomnia in children and … doi:10.1089/cap.2013.0059 PubMed
- [15] Hwan-Soo Jang et al.. Pharmacol Biochem Behav. 2012. L-theanine partially counteracts caffeine-induced sleep disturbances in rats. doi:10.1016/j.pbb.2012.01.011 PubMed
- [16] Benjamin S Weeks. Med Sci Monit. 2009. Formulations of dietary supplements and herbal extracts for relaxation and anxiolytic action: Relarian. PubMed
Aviso Legal da FDA: Estas declarações não foram avaliadas pela Food and Drug Administration. Os produtos e informações neste site não se destinam a diagnosticar, tratar, curar ou prevenir qualquer doença. As notas de evidência apresentadas são baseadas em nossa análise de pesquisas revisadas por pares publicadas e não constituem aconselhamento médico. Sempre consulte seu profissional de saúde antes de iniciar qualquer regime de suplementação.