Summary
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What is green tea?
Green tea is made by lightly steaming freshly cut leaves of Camellia sinensis. It is higher in catechins (polyphenols) such as EGCG than black tea. It is sold in many forms such as tea bags, loose teas, matcha powders, bottled teas, and as supplements containing extracts with high concentrations of catechins. Green tea also contains caffeine — about half as much per cup as in coffee (see What It Is). -
Health benefits of green tea:
Health benefits are generally associated with catechins in green tea, most notably EGCG. Benefits include a modest reduction in LDL cholesterol, reduced growth of uterine fibroids and associations with lower risks of cardiovascular disease, certain cancers and type 2 diabetes. These benefits are generally associated with consumption of 3 or more cups per day. Studies with green tea supplements typically provide 200 mg to 300 mg per day. The evidence regarding weight loss and memory benefits is mixed and may relate to the caffeine in green tea (see What It Does). -
What did CL's tests of green tea products find?
Our tests (see What CL Found) found shockingly little EGCG (0.64 mg to 7.6 mg) per cup in four brands of brewable teas (tea bags or loose tea), but much higher amounts (up to 90.8 mg) in several others. Supplements provided 26.4 mg to 250 mg of EGCG per serving. Matcha powders provided about 100 to 150 mg of EGCG per teaspoon (2 grams). 
Which is the best green tea?
Our Top Pick among green tea in tea bags stood out for having excellent flavor and providing one of the highest amounts of EGCG at modest cost. Our Top Pick for matcha costs just 1/3 the price of a nearly identical matcha powder and provides 50% more EGCG. We chose both a low-dose and a high-dose Top Pick among green tea supplements. Although green tea leaves can accumulate toxic lead, none of the products were found to provide significant amounts of lead. (see ConsumerTips).-
Green tea safety, side effects, and drug interactions:
Green tea can interfere with a range of drugs. Liver toxicity is a concern with high doses of EGCG from green tea supplements, particularly if not consumed with food. Green tea contains a small amount of fluoride and regularly consuming very large amounts of green tea can cause fluorosis, a condition that makes bones and teeth brittle. Avoid excessive green tea when pregnant. Don't drink very hot tea, as this has been associated with higher risk of gastric cancer (see Concerns and Cautions). Be aware that plastic (nylon) tea bags may release microplastics as well as reduce levels of EGCG in tea (See ConsumerTips).
