SUPPORTS HEALTHY IMMUNE RESPONSE: Quercetin can help stabilize cells that release histamine in the body. ANTIOXIDANT : Nutrissence Quercetin 500mg contains flavonoids that have strong antioxidant properties. ANTI-INFLAMMATORY: Quercetin can also act like an antihistamine and an anti-inflammatory NO PRESERVATIVES & NO GMO - Contains NO GMO ingredients, preservatives, artificial flavor, milk, lactose, soy, or gluten. MANUFACTURED IN USA: Made in the USA in an FDA approved facility following cGMP guidelines.