The effects of L-theanine consumption on sleep outcomes: A systematic review and meta-analysis
Bulman A, D'Cunha NM, Marx W, Turner M, McKune A, Naumovski N
Published in Sleep Medicine Reviews
Methodology
Systematic review and meta-analysis of 19 randomised controlled trials (18 pooled) of L-theanine supplementation on sleep outcomes across five databases through September 2024
Key Findings
L-theanine significantly improved subjective sleep onset latency (SMD 0.15, 95% CI 0.01-0.29), subjective daytime dysfunction (SMD 0.33) and overall subjective sleep quality (SMD 0.43).
Conclusions
L-theanine may have a modest role in managing sleep disturbances, particularly subjective sleep onset and quality.
Limitations
Effect sizes are small, outcomes are largely subjective, and few trials tested pure L-theanine rather than combination products.
Supplements Studied
L-theanine was shown to significantly improve subjective sleep onset latency (SMD = 0.15, 95 % CI [0.01, 0.29], p = 0.04; n = 10 studies)
Related Health Concerns
Study Details
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Disclosures
Funding
Not reported
This information is for educational purposes only. Always consult a healthcare professional before starting any supplement regimen.