Activated Quercetin from Source Naturals is a unique bioflavonoid blend derived from plant sources. Quercetin is an antioxidant that protects blood vessels and gives the immune system a boost. Bromelain is a pineapple enzyme that may assist the body in times of stress. Vitamin C helps to support the immune system. Contains no yeast dairy egg gluten soy or wheat. Contains no sugar preservatives or artificial color flavor or fragrance.