Quercetin is a naturally occurring flavonoid (plant pigment) which is found in many plants including onions, apples, kale, green tea, and multiple species of berries. Its antioxidant activity makes these plants resilient and protects their cells from environmental stressors.  The antioxidant action of quercetin is recognized for numerous human health benefits. Quercetin has a long history of traditional use, with current research showing promise for potential added health benefits. Each vegetable capsule contains: Other ingredients: Vegetable magnesium stearate and silicon dioxide in a non‑GMO vegetable capsule composed of vegetable carbohydrate gum and purified water.Adults: Take 1 capsule daily or as directed by your health-care practitioner. Duration of use: Consult a health-care practitioner for use beyond 12 weeks.