Potent flavonoid antioxidant found in onions, apples, and berries. Supports immune function, reduces inflammation, and has natural antihistamine properties.
How it works
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
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
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
4 products compared across Australian retailers. Sorted by price per serve.
Scroll for more
| Product | Price | /serve | |
|---|---|---|---|
Best BulkSupplements BulkSupplements Quercetin Powder BulkSupplements | $24.90 | $0.12 | |
NOW Foods NOW Quercetin with Bromelain iHerb | $28.90 | $0.24 | |
Life Extension Life Extension Bio-Quercetin Life Extension | $22.00 | $0.37 | |
Thorne Thorne Quercetin Phytosome Thorne | $38.00 | $0.63 |
Prices in AUD. Some links are affiliate links — we may earn a commission at no extra cost to you.
Get a personalised supplement stack based on your health goals, age, medications, and preferences.
Also consider
Vitamin
Powerful antioxidant essential for collagen synthesis and immune function.
Vitamin
Essential vitamin for immune regulation, bone health, and mood.
Mineral
Essential mineral involved in immune function, wound healing, and cell division.
Herb
Elderberry (Sambucus nigra) is a dark purple berry rich in anthocyanins and flavonoids that support immune function. Available in capsules, gummies, syrups, and liquid extracts, elderberry is one of Australia's most popular natural immune supplements. Clinical trials show elderberry may reduce the duration and severity of colds and flu by up to 4 days.
Quercetin has 2 known interactions. Check if it's safe with your medications.
Price drops, new products, and research updates for quercetin supplements. One email per week, unsubscribe anytime.
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.