-Grape Seed Extract is naturally rich in polyphenols known as oligomeric proanthocyanidins (OPCs). These active compounds may also be found in a variety of plants and herbs, including green tea, bilberry, and cranberry, and are significant in health-promoting traditions across the world. In addition to its cardiovascular benefits, proanthocyanidin molecules have antioxidant properties that aid in the battle against free radicals in the body. Free radicals can induce oxidative stress, which can harm cells.