Tomorrow's Nutrition SunTheanine improves focus and concentration, reduces stress without drowsiness, and improves quality of sleep. Suntheanine is an award winning L-theanine produced by the Japanese company Taiyo, via a patented enzymatic process, resulting in 100% pure L-theanine. Human clinical trials have shown Suntheanine to promote an alert state of relaxation without drowsiness. Additional human clinical research suggests that Suntheanine may have application in improving the quality of sleep, diminishing normal symptoms of premenstrual syndrome (PMS), improving learning performance, heightening mental acuity, promoting concentration, reducing negative side effects of caffeine and supporting the immune system. Suntheanine has been shown to be safe based on numerous favorable toxicology and efficacy studies. Unlike other stress reducing supplements, Suntheanine does not cause drowsiness. Suntheanine has been consumed in beverages, foods and supplements since 1994 with no indication of adverse reactions or contraindications.