Quercetin is an inexpensive plant compound found in common foods. Its most reliable benefit is a modest lowering of blood pressure, with fairly consistent reductions in uric acid and inflammation. Allergy, immune, and exercise uses rest on weaker evidence, and its longevity appeal remains largely unproven. Poorly absorbed, so form, dose, and taking it with food matter. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Blood pressure | <120/80 mm Hg | Primary demonstrated benefit |
| High-sensitivity CRP | <1.0 mg/L | Tracks the anti-inflammatory effect |
| Uric acid | 3.5–5.5 mg/dL | Reflects xanthine oxidase inhibition |
| Fasting glucose / HbA1c | <90 mg/dL / <5.4% | Monitors metabolic effect |
| LDL-cholesterol | <100 mg/dL | Captures the variable lipid effect |
| eGFR / creatinine | eGFR >90 mL/min/1.73m² | Safety check given high-dose kidney concern |
| ALT / AST | ALT <25 U/L (men <30), AST <25 U/L | Safety check for long-term use |
Cadence: Baseline before starting; recheck at 8–12 weeks, then every 6–12 months for long-term use