Quercetin belongs to a water-soluble group of plant pigments called flavonoids found in fruits, vegetables, and herbs. It exists in a variety of foods like apples, berries, grapes, onions, shallots, Brassica vegetables, tea, tomatoes, nuts, seeds, and more.

Quercetin demonstrates many biological effects. It has been studied for its anti-inflammatory, antioxidant, anticarcinogenic, and anti-viral activity along with immune and liver support. Quercetin helps support healthy respiratory and immune function and reduce allergic response.* Quercetin also may help lower blood sugar and improve insulin sensitivity.