Grapeseed Extract is an herbal medicine used for treating vein problems, including varicose veins (large veins that are usually seen in the legs); eye probles like diabetic retinopathy (eye problems in diabetics); premenstrual syndrome; and to help prevent diseases. Other names for Grape Seed Extract include: Vitis Vinifera, PCO, Pycnogenol, and OPC. Check with your doctor before taking Grape Seed Extract.