Quercetin
Potent flavonoid antioxidant found in onions, apples, and berries. Supports immune function, reduces inflammation, and has natural antihistamine properties.
How it works
Mechanism of Action
Stabilises mast cells to reduce histamine release. Inhibits inflammatory enzymes (COX-2, lipoxygenase). Acts as a zinc ionophore, helping zinc enter cells to support immune function.
Evidence-based uses
What Quercetin Is Used For
Natural antihistamine and zinc ionophore. Pairs well with zinc for immune support. May reduce allergy symptoms.
Clinical Evidence
Quercetin 1000mg/day for 3 weeks significantly reduced upper respiratory tract infections (1 of 20 vs 9 of 20 in placebo) in trained athletes.
Safety
Interactions & Warnings
Quercetin may increase cyclosporine levels by inhibiting CYP3A4 and P-glycoprotein. Use with caution.
Quercetin may compete with fluoroquinolone antibiotics for DNA gyrase binding. Separate doses by at least 2 hours.
Compare prices
Buy Quercetin in Australia
5 products compared across Australian retailers. Sorted by price per serve.
| Product | Price | /serve | |
|---|---|---|---|
Best BulkSupplements BulkSupplements Quercetin Powder BulkSupplements | $24.90 | $0.12 | Buy |
Doctor's Best Doctor's Best Quercetin Bromelain Amazon AU | $32.95 | $0.18 | Buy |
NOW Foods NOW Quercetin with Bromelain iHerb | $28.90 | $0.24 | Buy |
Life Extension Life Extension Bio-Quercetin Life Extension | $22.00 | $0.37 | Buy |
Thorne Thorne Quercetin Phytosome Thorne | $38.00 | $0.63 | Buy |
Prices in AUD. Some links are affiliate links — we may earn a commission at no extra cost to you.
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This information is for educational purposes only and is not intended as medical advice. Always consult a healthcare professional before starting any supplement. Evidence ratings are based on peer-reviewed clinical research. Individual results may vary.