Green tea caffeine taken in proper quantity stimulates every organ in the body. A cup of green tea will help clear a dull mind in the morning. It is also thought that small amount of caffeine present in a normal serving of green tea (9 mg of caffeine) can stimulate the skeletal muscles and facilitate muscular contraction. It is quite refreshing to have a cup of green tea in the middle of work, and we find it noteworthy that there is new scientific support for such old customs as the afternoon tea ritual. The caffeine in green tea is mostly extracted in the process of drying leaves. Green tea caffein combines with catechin in the brewing water, and is rather milder than other caffeine-containing beverages. Even so, for those people who are sensitive to caffeine, it is safer for to drink weak green tea.