This fact sheet provides basic information about green tea—common names,
uses, potential side effects, and resources for more information. All types of tea
(green, black, and oolong) are produced from the Camellia sinensis plant using
different methods. Fresh leaves from the Camellia sinensis plant are steamed to
produce green tea.
Common Names—green tea, Chinese tea, Japanese tea
Latin Name—Camellia sinensis
What It Is Used For
• Green tea and green tea extracts, such as its component EGCG, have been
used to prevent and treat a variety of cancers, including breast, stomach,
and skin cancers.
• Green tea and green tea extracts have also been used for improving mental
alertness, aiding in weight loss, lowering cholesterol levels, and protecting
skin from sun damage.
How It Is Used
Green tea is usually brewed and drunk as a beverage. Green tea extracts can be
taken in capsules and are sometimes used in skin products.
What the Science Says
• Laboratory studies suggest that green tea may help protect against or slow the
growth of certain cancers, but studies in people have shown mixed results.
• Some evidence suggests that the use of green tea preparations improves
mental alertness, most likely because of its caffeine content. There are not
enough reliable data to determine whether green tea can aid in weight loss,
lower blood cholesterol levels, or protect the skin from sun damage.
• NCCAM is supporting studies to learn more about the components in green tea
and their effects on conditions such as cancer, diabetes, and heart disease.
Side Effects and Cautions
• Green tea is safe for most adults when used in moderate amounts.
• There have been some case reports of liver problems in people taking
concentrated green tea extracts. This problem does not seem to be
connected with green tea infusions or beverages. Although these cases are
very rare and the evidence is not definitive, experts suggest that