Quercetin

Quercetin (CAS 117-39-5) is permitted in EU cosmetics under Regulation (EC) No 1223/2009 without specific concentration limits, and is approved for cosmetic use in the US with no pre-market authorization required. Dermal absorption into the stratum corneum is approximately 18%, with limited systemic exposure due to extensive first-pass metabolism. In vitro mutagenicity signals are not expressed in vivo; renal adenomas observed in male rats at high oral doses are considered species-specific and not relevant to topical human use. The EU classifies Quercetin as "permitted". Safety rating: GOOD.

Quercetin EU regulatory status: permitted. Maximum allowed concentration: 0.1–0.5%. This is based on EU Regulation 1223/2009 and its amendments.

Quercetin functions as: Flavonol polyphenol ubiquitous in plant kingdom (onion skin, apple peel, blueberry, capers, green tea). Mechanisms: direct free-radical scavenging (hydroxyl, superoxide, peroxyl, alkoxyl); chelation of pro-oxidant metal cations (Cu2+, Fe2+) blocking Fenton reactions; inhibition of collagenase, elastase, and hyaluronidase preserving ECM structural integrity; anti-inflammatory via 5-LOX, COX-2, and NF-kB pathway inhibition; upregulation of endogenous antioxidant enzymes. Anti-aging, antioxidant, and anti-inflammatory active. Poor water solubility (~0.01 mg/mL) limits aqueous formulation; encapsulation (liposomes, cyclodextrins, nanoemulsions) required for effective delivery.. It is classified as a Active Ingredient in our database. CAS number: 117-39-5.

not established The Margin of Safety (MoS) is calculated using SCCS methodology. A MoS above 100 is generally considered safe. Use the MoS Calculator tool to calculate MoS for your specific formulation and product category.