Source: Examine.com — Quercetin — 500–1,000 mg/day for antioxidant/immune and blood-pressure endpoints.
A flavonoid antioxidant found in onions, apples and capers.
Stabilizes mast cells (reducing histamine) and neutralizes free radicals.
Safe; poorly absorbed on its own. Very high long-term doses warrant caution with kidney issues.
| Per serving | |
|---|---|
| Typical branded single-ingredient product | $0.58 |
| Bulk powder at the clinical dose (250g 95%, $42.97) | $0.09 |
Buying bulk powder instead of a branded bottle saves about 85% per serving.
Bulk price: $42.97/250g → Alt source: $12.99/125gEducational only — not medical advice. Grades and clinical doses are computed from public labels against sourced research (citations on the main site); prices last verified 2026-07-21. Expensive Powder has no sponsors; bulk links may earn an affiliate commission, which never affects a grade. Talk to a clinician before starting any supplement.