Green tea extract is sold as a nutritional product and is not intended to be prescribed for any specific condition. Researches often base the amount of tea given to research subjects on the amount of Green Tea typically consumed in Asian countries--about 3 cups (750 ml) per day (providing 240-320 mg of polyphenols).

Tablets and capsules containing standardized green tea extracts of polyphenols, particularly EGCG, are available. Some provide up to 97% polyphenol content--which is equivalent to drinking 4 cups (1,000 ml) of tea. Many of these standardized products are decaffeinated.