Quercetin is a powerful flavonoid with a wide range of health benefits, including its ability to reduce inflammation, eliminate pain, protect against cardiovascular diseases, lower blood pressure, manage diabetes, prevent certain cancers, boost the immune system, and reduce irritation of the skin. What Is Quercetin? It is a flavonoid, which means that it is a plant pigment that is similar in molecular structure to a flavone. It is also considered a very powerful antioxidant and is typically the main component in the red and orange pigmentation in various fruits and vegetables. You can also find quercetin as a coloring agent in wine and various teas.