The green tea caffeine content varies 12-50mg, depending on where the plant was grown, the brand, the brew time and whether the leaves are used for a second steep.

It stimulates the central nervous system, which is what "wakes you up". It was first extracted from the rhiamon sinensis (the tea plant) leaves in 1888. Besides, the green tea caffeine may actually be good for your health. Is Green Tea Caffeine Good For You.

Of the brands on the market, Sobe probably contains the least, at 14mg per eight ounce cup. They do contain less of the stimulant, but the processes that manufactures use to decaffeinate the leaves are of questionable safety. Theophylline is one of the caffeine-like substances. Theobromine is the other caffeine-like substance in candide sinensis leaves. The second steep would contain only about 12mg. Decaffeinated teas are not caffeine-free.

Solvents are generally used and one of the commonly used solvents is a probable carcinogen.

By 1916, it was being used to reduce swelling. It has anti-inflammatory activity, relaxes smooth muscles, increases heart muscle activity and blood flow.

It actually contains "caffeine-like" substances.