Quercetin for Allergy Relief

Research suggests that quercetin possesses anti-allergic properties relevant to conditions such as allergic rhinitis, allergic conjunctivitis, asthma, and atopic dermatitis, with laboratory and animal studies consistently showing that it can suppress mast cell activation, inhibit histamine release, reduce pro-inflammatory signaling, and help rebalance immune responses that drive allergic reactions. The available evidence spans multiple review articles, a 2025 meta-analysis pooling 13 randomized controlled trials on polyphenols for allergic rhinitis, and at least one small double-blind placebo-controlled trial in which a bioavailable quercetin formulation was associated with statistically significant reductions in pollen allergy symptoms including eye itching, sneezing, and nasal discharge compared to placebo. Studies indicate that the overall direction of findings is consistently supportive, though researchers and reviewers across multiple publications note important limitations: human clinical trials specifically on quercetin as a standalone treatment remain few and small in scale, the quality of evidence in the meta-analysis was rated low to very low, and quercetin's poor natural bioavailability introduces variability in how well it is absorbed and studied across different formulations. The current body of evidence is considered promising but preliminary, and reviewers consistently call for larger, more rigorously designed clinical trials before firm conclusions about quercetin's role in allergy management can be drawn.