Natural Factors Grape Seed super strength concentrate is a 100:1 concentrate guaranteed to contain a minimum of 95% polyphenols and 80% proanthocyanidins. Unlike some grape seed products, Natural Factors Grape Seed (Vitis vinifera) is not made from oven -or- sun-dried seeds. It is made exclusively from fresh, non-GMO grape seeds separated during juice production. This method produces a high ratio of the key polyphenols. The extraction process uses water and ultra filtration; not organic or alcohol solvents. The result is a 100:1 concentrate of pure, potent polyphenols.