What it is
Quercetin is a flavonoid pigment found widely across the plant kingdom and used in skincare primarily for its antioxidant properties. In sunscreens it is typically included at low levels to help support the formula's antioxidant profile rather than to contribute UV protection. It is yellow in color, which can be a formulation consideration at higher concentrations.
Safety & warnings
Generally well tolerated as a topical antioxidant at the low levels used in cosmetics. It is intensely yellow, so formulators manage its concentration to avoid staining; sensitivity at typical use levels is uncommon.
Origin & sourcing
Naturally occurring flavonoid found in many plants, including onions, apples, and various fruits and leaves; the cosmetic ingredient may be plant-extracted or produced synthetically.
Questions everyone asks
What is quercetin?
It is a naturally occurring plant flavonoid used in skincare for its antioxidant activity.
Why is it in a sunscreen?
It is added as an antioxidant to support the formula; it is not a UV filter and does not provide sun protection.