Quercetin ●
TL;DR. This ingredient functions primarily as an antioxidant active, helping protect formulas and skin surface lipids from oxidative stress. It may also be used for calming and tone-support claims in leave-on skin care.
What does Quercetin do in a cosmetic formula?
This ingredient functions primarily as an antioxidant active, helping protect formulas and skin surface lipids from oxidative stress. It may also be used for calming and tone-support claims in leave-on skin care.
Is Quercetin clean?
From a clean-beauty perspective, it is generally well tolerated and is not a common restricted-list concern. Practical issues are more about low solubility, yellow color, and the need for careful formulation than about routine irritation.
Is Quercetin sustainable?
This material is commonly sourced from botanicals and is expected to be biodegradable rather than environmentally persistent. Its sustainability profile depends on plant source, extraction yield, and whether lower-impact solvents are used.
Is Quercetin COSMOS-approved?
It can fit COSMOS-natural and COSMOS-organic frameworks when obtained from approved plant sources using compliant extraction and purification methods. It aligns well with Green Chemistry when renewable feedstock, benign solvents, and low-waste extraction are used.
How does Quercetin work chemically?
The molecule is a polyphenolic flavonol with multiple hydroxyl groups, which explains its antioxidant behavior, metal-chelating capacity, strong color, and limited water solubility. Typical cosmetic use is often in the 0.01% to 1% range, with better handling in glycols, ethanol, liposomes, or encapsulation systems, and protection from high pH, light, and metal ions can improve stability.
Last updated 2026-05-13