ResveragenItem Description Resveratrol is a polyphenolic compound with antioxidant activity found in grapes, wine, blueberries, cranberries, and peanuts. While red wine has been popularized as an important source of resveratrol, amounts vary widely. The maximum content of resveratrol in red wine extracts available for use in dietary supplements is 20%. In contrast, root extracts of Japanese Knotweed (Polygonum cuspidatum) provide up to 50% trans resveratrol