Systematic Review: The Role of L-Theanine in Enhancing Sleep Efficiency and Recovery
- 4 days ago
- 1 min read
A 2025 systematic review published in Nutritional Neuroscience critically appraised 13 clinical trials (involving 550 participants) to determine the efficacy of L-theanine as a standalone sleep aid. The review sought to establish whether this non-protein amino acid could serve as a viable, non-sedative alternative to traditional pharmaceutical sleep interventions.
The analysis led to several key scientific conclusions:
Optimal Dosage Range: The review identified that daily doses between 200 mg and 450 mg are the most effective for supporting healthy sleep architecture in adults. Doses within this range were found to be safe and consistently well-tolerated across the study populations.
Sleep Continuity and Latency: Data from the included randomized controlled trials (RCTs) showed significant improvements in sleep latency (the time it takes to fall asleep) and sleep efficiency (the ratio of time spent asleep to time spent in bed).
Subjective Refreshment: Unlike sedative-hypnotic drugs that can cause morning "grogginess," L-theanine was associated with higher levels of subjective refreshment and physical recovery upon waking. This suggests that L-theanine improves sleep by facilitating relaxation and reducing nocturnal anxiety rather than by inducing heavy sedation.
Broad Applicability: Beneficial effects were observed not only in healthy adults but also in specific populations, including individuals with ADHD and those experiencing high levels of daily stress, indicating that L-theanine's sleep-promoting properties are largely driven by its ability to modulate the central nervous system’s stress response.
The researchers concluded that while L-theanine is not a "knock-out" sedative, it is a highly effective tool for improving the overall quality and restorative nature of sleep through natural relaxation pathways.
Article: Examining the effect of L-theanine on sleep: a systematic review of dietary supplementation trials
Comments