All tea originates from the leaf of the camellia sinensis leaf so black, oolong, green and white tea all contain caffeine however it is in different levels. Generally the most caffeine is found in black tea which explains why it is a popular choice for breakfast, to kick start the day.
Tea contains about 50 milligrams of caffeine per cup. For most healthy adults up to six cups of tea per day is considered safe (around 300 milligrams) – if you find you have a sensitivity to caffeine switch to the herbals and fruits. Some people stop drinking caffeine after 3.00pm each day.