Since ancient times it has been said that drinking green tea helps promote relaxation and an overall feeling of well-being.  A pioneer in the science of green tea, Taiyo found this relaxation effect to be due to the presence of the amino acid L-theanine. Suntheanine is the trade name for Taiyo's patented, pure form of L-theanine. Suntheanine has been used in more clinical studies than any other L-theanine. Studies show Suntheanine has significant effects on anxiety and other stress-related mechanisms in the body, as well as the ability to promote relaxation and sleep.