High-quality quercetin enhanced with lemon bioflavonoids, rutin, and citrus hesperidin.* Quercetin is an antioxidant bioflavonoid found throughout the plant kingdom in rinds and barks. Food sources include onions, red wine, green tea, and St. John’s wort. Quercetin is known for its immune-balancing and antioxidant effects and helps protect the lungs from seasonal distress and the damaging effects air pollution.* These nutrients can also help stabilize cell membranes, and support the integrity of mast cells, and provide nutritional supplement for normal immune system function.* Quercetin and bioflavonoids have been shown to support vascular health, and to have gastro-protective and cardio-protective properties.*