Green tea does contain caffeine.Â An 8-ounce serving ofÂ brewed greenÂ tea can contain 24Â to 45Â milligrams of caffeine. However, other types of teas and coffee can have a higherÂ quantity of caffeine.
For example, in the same quantity of brewed black tea, the caffeine content can be as high as 70 milligrams. Similarly, comparing the caffeine content in equivalent servings of green tea and black coffee, the caffeine content in coffee is higher, being in the range 95 to 200 milligrams.
Caffeine is a stimulant naturally found in green tea. Some others are theobromine and theophylline. Although green tea has a stimulant effect, it may be counterbalanced by the amino acid called L-theanine that has a calming effect and also may help with concentration and memory.
Those who want to drink green tea but without the caffeine can opt for decaffeinated green tea.