Green tea extract is a substance obtained by extracting camellia leaves, which are often used to make green tea, black tea and oolong tea. Green tea extract has many health benefits and many have been scientifically proven. These benefits include potential anti-cancer properties and powerful antioxidants that protect the body from free radical damage.

Green tea extract, like many herbs, uses a standard manufacturing process to ensure that certain active ingredients are retained. The active ingredient in the green tea extract is a polyphenolic substance, which is in the form of catechin and epigallocatechin gallate (EGCG), and flavonoids. Polyphenols, flavonoids, catechins and EGCG are powerful antioxidants known to inhibit and reduce the spread of specific cancer cells. The antioxidant activity of epigallocatechin gallate in green tea extract is said to be more than 100 times stronger than vitamin C or E.

Green tea extract can also improve cardiovascular circulation, reduce appetite and promote fat oxidation by reducing bad cholesterol. But these arguments have not been widely recognized by the research community, because these data are usually based on animal experiments, and few have been clinically validated by humans.