Quercetin
flavonoid
What it isDietary flavonoid antioxidant and mast cell stabilizer.
Why this oneIt is among the most studied flavonoids for allergic and inflammatory conditions.
What limits itPoor oral bioavailability, and it inhibits CYP3A4 and P-gp at supplement doses. Clinical evidence remains weak.
FDA-approved for
- dietary flavonoid (no approved indication)
Off-label
- allergic rhinitis and antioxidant supplementation (limited evidence)
FDA label
Read the full label on DailyMed ↗
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Not stated on label (OTC homeopathic/supplement oral drops) | Adults & children ≥12 yr | 10 drops SL up to TID | 10 drops SL up to TID | 10 drops SL TID |
Renal Undefined
Hepatic Undefined
Instructions
- Place drops under the tongue 30 min before or after meals.
- Children <12 yr: consult a physician before use.
Available strengths
- cap 500 mg
Pregnancy Undefined
Lactation Undefined
Cost
Quercetin (FLAVONOID)
| Strength | #/mo | generic $/mo | CostPlus | |
|---|---|---|---|---|
| 500 mg | cap | 90 TID | not offered |
NADAC is a voluntary CMS survey of what retail community pharmacies pay for the drugs they stock. Quercetin is dispensed outside retail pharmacies, so it rarely appears on surveyed invoices.
NO BOXED WARNINGS
Principal riskPoor oral bioavailability, and it inhibits CYP3A4 and P-gp at supplement doses