Dietary Supplement Proanthocyanidin Complex Pycnogenol is a natural plant product made from the bark of the European coastal pine, Pinus maritima. Pycnogenol is rich in proanthocyanidins, a special class of water-soluble antioxidant flavonoids, which are excellent free radical scavengers. Proanthocyanidins are believed to play an important role in maintaining good health.