Quercetin is an antioxidant bioflavonoid found in vegetables, fruits, and herbs. It supports cellular health throughout the body by scavenging the free radicals responsible for aging, poor health, and chronic illness. Bioflavonoids such as quercetin are essential for the proper use of vitamin C. When taken in the form of enzymatically modified isoquercetin (EMIQ), they have a significant anti-allergy effect. Natural Factors offers a range of single quercetin supplements and combined antioxidant formulas for comprehensive support.