Non-GMO. gluten-free. and vegetarian product provides 5 mg quercetin in one capsule. Preclinical studies demonstrate quercetin affects immunity by acting on leukocytes and other immune cells*. Quercetin supports healthy cardiovascular function and helps maintain healthy blood pressure levels already in the normal range*. Free radical-scavenging antioxidants like quercetin protect cells from harmful free radicals and inhibit oxidative stress*.