NOW® Grape Seed Extract is a highly concentrated natural extract with a minimum of 90% Polyphenols, including Oligomeric Proanthocyanidins (OPCs), which are the potent water-soluble free radical scavenging compounds found in Grape Seeds. A growing body of research indicates that Grape Seed OPCs may help to support the health of tissues by supporting a robust response to oxidative and metabolic stress.