Resveratrol is a natural polyphenol found in red wine, peanuts and in some plants, including the herb Polygonum cuspidatum. It is a small molecule, classified as a stilbene. Polyphenols, such as resveratrol, possess antioxidant properties that help fight free-radicals in the body. Free radicals can contribute to oxidative stress, and in turn may contribute to the premature aging of cells.