Bioflavonoid type substance which is found in the bark of citric trees. Flavonoids are phenolic compounds naturally occurring that are abundantly present in plants and seaweed. We take it from fruits, vegetables, tea and red wine (as a few examples) Most important types are: anthocyanins, chalcons, flavonols, flavones, flavonoids and tannins. No risk for toxic nor side-effects in humans have been found. They appear naturally in the breast milk in amounts related to mother's diet. Attributed anti-oxidant activity and other properties that have not been fully shown yet, as amelioration of capillary vessel function which is a reason to be used for treatment of venous insufficiency (varicose veins) and prevention of arteriosclerosis.