Quercetin Interactions

Quercetin inhibits the sulfotransferase and UDP-glucuronosyltransferase enzymes that rapidly clear resveratrol, prolonging its plasma half-life and free fraction. The two polyphenols also act synergistically on antioxidant and SIRT1-related longevity pathways in cell and animal studies.

Quercetin is a flavonoid with antioxidant, anti-inflammatory, and antiviral activity; vitamin C 'recycles' oxidized quercetin back to its active form, prolonging its effect and preventing prooxidant byproducts. The combination has been studied for immune support and antiviral effects.

Quercetin inhibits the same UDP-glucuronosyltransferase and CYP3A4 enzymes that rapidly metabolize curcumin, raising its plasma exposure, and both polyphenols share complementary anti-inflammatory and antioxidant pathways. In vitro intestinal models and animal studies show the combination increases apical-to-basal uptake of curcumin and amplifies NF-kB pathway suppression.

Fisetin and quercetin are structurally related flavonols with overlapping but distinct senolytic and anti-inflammatory mechanisms. Fisetin was identified in a Mayo Clinic screen as the most potent natural senolytic, while quercetin has been clinically tested as part of the dasatinib + quercetin senolytic combination, and the two together broaden the senolytic and antioxidant coverage.

Bromelain is a proteolytic enzyme complex from pineapple that improves quercetin absorption (reportedly 2-3x) and adds independent anti-inflammatory effects (fibrinolytic activity, COX modulation, bradykinin reduction). The pair is commonly co-formulated for inflammation, allergy, and immune support.