From the Guidelines
L-theanine is not recommended for stress and anxiety management due to lack of strong evidence supporting its use as stated in the guideline evidence 1. The guideline evidence from the Journal of Clinical Oncology in 2018 1 does not support the use of ingested dietary supplements, including L-theanine, to manage treatment-related adverse effects. Instead, the recommendations include music therapy, meditation, stress management, and yoga for anxiety/stress reduction, as well as meditation and yoga to improve quality of life 1. Key points to consider for stress and anxiety management include:
- Music therapy, meditation, and yoga are recommended for reducing anxiety and stress
- These methods can be used in conjunction with other therapies to improve overall well-being
- The lack of strong evidence for L-theanine and other dietary supplements means that other methods should be prioritized for managing stress and anxiety. It's essential to prioritize methods with strong evidence, such as meditation and yoga, for managing stress and anxiety, rather than relying on supplements like L-theanine.
From the Research
Recommended Dosage and Usage of L-theanine
- The recommended dosage of L-theanine for stress and anxiety management is between 200 to 400 mg per day, as suggested by studies 2, 3.
- This dosage has been shown to be safe and effective in reducing stress and anxiety in both acute and chronic conditions 2.
- L-theanine may be taken for up to 8 weeks, with some studies suggesting that longer-term use may require further investigation 2, 3.
Effects of L-theanine on Stress and Anxiety
- L-theanine has been shown to reduce psychological and physiological stress responses, including heart rate and salivary immunoglobulin A (s-IgA) responses 4.
- It may also improve cognitive function, particularly attention and working memory, in middle-aged and older subjects 5.
- The anxiolytic and anti-stress effects of L-theanine may be attributed to its ability to inhibit cortical neuron excitation and attenuate sympathetic nervous activation 4.
Safety and Precautions
- L-theanine is generally considered safe, with a good safety profile based on toxicology studies 6.
- However, caution is warranted when using L-theanine supplements at pharmacologic doses, particularly in the absence of rigorous human clinical trials 6.
- Cases of hepatotoxicity associated with the consumption of green tea extract have been reported, highlighting the need for further investigation into the potential risks and benefits of L-theanine supplementation 2.