L-Theanine is a naturally occurring, unique amino acid found in green tea leaves. R3 Health’s L-Theanine is Suntheanine^® – the most respected and clinically tested L-Theanine on the market.* L-Theanine may promote a sense of relaxation without causing drowsiness.* L-Theanine has also been found to reduce feelings of stress and anxiety and may be useful in reducing the negative side effects of caffeine.*