According to the Lipton website, Lipton green tea has 35 milligrams of caffeine per one-teabag serving, less than most other teas. As a comparison, Lipton's black tea has 55 milligrams of caffeine... According to the Lipton website, Lipton green tea has 35 milligrams of caffeine per one-teabag serving, less than most other teas. As a comparison, Lipton's black tea has 55 milligrams of caffeine per serving.