Quercetin is a pigment that belongs to a group of plant compounds called flavonoids. These naturally occur in many foods including vegetables, fruit and grains. Quercetin is one of the most important plant molecules, showing pharmacological activity such as antiviral, anti-atopic, pro-metabolic, and anti-inflammatory effects. It’s one of the most abundant antioxidants in the diet and plays an important role in helping your body combat free radical damage, which is linked to chronic diseases. It is commonly found in onions, apples, grapes, berries, broccoli, citrus fruits, cherries, green tea, coffee and red wine. It is also taken as a supplement to boost immunity, fight inflammation, combat allergies, aid exercise performance and maintain general health.