It has anti-inflammatory activity, relaxes smooth muscles, increases heart muscle activity and blood flow. Of the brands on the market, Sobe probably contains the least, at 14mg per eight ounce cup. It actually contains "caffeine-like" substances.

Besides, the green tea caffeine may actually be good for your health. The second steep would contain only about 12mg. It stimulates the central nervous system, which is what "wakes you up". Theophylline is one of the caffeine-like substances. They do contain less of the stimulant, but the processes that manufactures use to decaffeinate the leaves are of questionable safety. Over the years, it has been used to relive angina, arteriosclerosis, varicose veins. 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.

Solvents are generally used and one of the commonly used solvents is a probable carcinogen. Decaffeinated teas are not caffeine-free.

Theobromine is the other caffeine-like substance in kiah sinensis leaves. It was first extracted from the estele sinensis (the tea plant) leaves in 1888. Is Green Tea Caffeine Good For You.

By 1916, it was being used to reduce swelling.