As its name implies, grape seed extract is derived from the small seeds (and occasionally the skins) of red grapes–the same kind that are pressed to make wine. Used extensively in Europe, grape seed extract is rich in flavonoids, phytochemicals that have antioxidant properties some consider even greater than the old standbys vitamin C and vitamin E. Antioxidants are believed to prevent and control numerous ailments by safeguarding cells against the ravages of unstable oxygen molecules called free radicals.