Quercetin is a secondary plant substance from the flavonoid group. As a yellow pigment, quercetin is mainly found in the outer layers and in the peels of fruits and vegetables. Onions, garlic, grapes, and selected herbs such as ginkgo biloba and St. John's wort are major sources of quercetin.
Quercetin is characterised by its strong antioxidant properties and is considered one of the most effective antioxidants among the flavonoids. Through its ability to neutralise free radicals, quercetin offers protection against oxidative stress. Quercetin also plays an important role in restoring other significant antioxidants such as vitamin C and vitamin E.
Due to its low water solubility, the biological availability of quercetin from food is low. Quercetin from Allvital contains a quercetin extract bound to phospholipids (Quercefit®), and thus has excellent bioavailability.
