Top 3 Benefits of L-Theanine for ADHD What is L-Theanine? L-Theanine, a compound found in green tea leaves, crosses the blood-brain barrier to promote calm and focus. Unlike stimulants, it enhances cognitive function and relaxation without causing drowsiness or crashes, making it particularly beneficial for those with ADHD. By boosting alpha brain waves, L-Theanine reduces stress and anxiety while improving attention and mental clarity. 1. Enhances Focus L-Theanine is remarkable for enhancing fo