Description: Quercetin is a popular flavonoid that is most commonly known for its presence in a number of plants. This includes apples, onions, capers and berries. Other common plants that contain flavonols like quercetin are horse chesnut, St. John's wart, ginkgo biloba and many more.We use high-quality quercetin in our supplements, combined with the ideal blend of bromelain, resveratrol, bioflavonoids and vitamins c. This makes sure that our Quercetin supplement is a potent antioxidant. Flavonoids work best in combination with each other which is why we've combined quercetin with resveratrol and citrus bioflavonoids. Quercetin's bioavailability is increased with the help of vitamin B5 and bromelain.