L-theanine is an amino acid primarily found in green tea leaves, and it is known for its potential to produce calming effects in humans without causing drowsiness. It affects brain functions and is of interest for managing stress and anxiety levels.

1. Anxiety and Stress Management: L-theanine has been studied for its anxiolytic and anti-stress properties. It can help reduce anxiety and psychological stress with a daily intake ranging from 200 to 400 mg for up to eight weeks¹. This makes it a potential supplement for improving mental health by addressing stress-related issues.

2. Effects on Brain Function: L-theanine is known to increase activity in the alpha frequency band of the brain, which is associated with a relaxed and alert mental state. This increased alpha activity has been noted after ingestion at doses as low as 50 mg, indicating its role in promoting mental relaxation and enhancing attention².

3. Combination with Other Compounds: L-theanine, especially when combined with caffeine, can positively affect cognition and mood by enhancing cerebral blood flow and boosting cognitive performance³.

Overall, L-theanine may serve as a beneficial supplement for those seeking to manage stress and improve cognitive function. However, more extensive clinical trials and research are recommended to better understand its long-term effects and therapeutic potential⁴.

Footnotes

1. Filipe Lopes Sakamoto, "Psychotropic effects of L-theanine and its clinical properties," PubMed, 2019. ↩

2. Anna C Nobre, "L-theanine, a natural constituent in tea, and its effect on mental state," PubMed, 2009. ↩

3. F. L. Dodd, "The effects of caffeine and L-theanine both alone and in combination on cerebral blood flow, cognition and mood," PMC, 2015. ↩

4. Jackson L Williams, "The effects of Green Tea Amino Acid L-Theanine Consumption on Stress and Anxiety Levels," PubMed, 2024. ↩