Supplement Scholar
Compound

Quercetin

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Quercetin. Flavonoid with antihistamine and senolytic effects; pairs with bromelain or vitamin C.

How it works. Inhibits mast cell degranulation; senolytic with dasatinib in animals.

What the research supports. 2 graded claims. Strongest: Reduces URI incidence in athletes (moderate).

How much to take. Typical dose: 500–1000 mg/d.

Side effects and interactions. 2 medication interactions listed. No serious side effects listed at normal doses.

Stacking. Pairs well with Bromelain, Zinc.

Forms. 1 forms. Pick one to open its profile.

Key studies. 9 studies cited. The strongest are listed with links to PubMed.

Community. Experiences from people who have tried Quercetin. Anecdotes are not medical advice.

Quercetin. Flavonoid with antihistamine and senolytic effects; pairs with bromelain or vitamin C.

Molecular structureC15H10O7 · 302.23 g/mol

What it is

Flavonoid with antihistamine and senolytic effects; pairs with bromelain or vitamin C.

Food sources

OnionsApplesCapers

Goals

Immune FunctionHealthy AgingChronic Inflammation

How it works

Inhibits mast cell degranulation; senolytic with dasatinib in animals.

Pathways

  • Mast cell stabilization
  • Senolysis

Effects

  • ↓Histamine release decreases
  • ↓Inflammatory markers decreases

What the research supports

Reduces URI incidence in athletesmoderate
Reduces allergic rhinitis symptomslimited

Strong: consistent results across large trials or meta-analyses. Moderate: several trials, mostly positive. Limited: small or mixed studies. Preclinical: animal or cell research only.

Typical dose
500–1000 mg/d
TimingConsistent daily timing recommended; split larger doses if GI tolerance is a concern.
With foodWith a meal containing fat for fat-soluble compounds; otherwise either.
Best formMost evidence is based on the quercetin dihydrate form.
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Side effects & interactions

Common side effects

  • Headache
  • Nausea

Medication interactions

CYP3A4 substratesmoderate

Inhibition.

Quinolonesmoderate

Reduced efficacy.

Check any supplement–medication combination with your pharmacist before starting.

Combines with

Pairs well

  • BromelainBoosts quercetin absorption.
  • ZincQuercetin acts as zinc ionophore.

Key studies

9 studies cited in total.

Quercetin and blood pressure: a meta-analysis ↗
Meta-analysis · J Am Heart Assoc · 2016

Significant reductions in systolic and diastolic BP.

PubMed: Quercetin — Reduces allergic rhinitis symptoms ↗
Systematic review · PubMed (NLM) · 2026

Opens current human and preclinical literature matching Quercetin and "Reduces allergic rhinitis symptoms". Filter by RCT, meta-analysis, or year on the results page.

PubMed: Quercetin — Reduces URI incidence in athletes ↗
Systematic review · PubMed (NLM) · 2026

Opens current human and preclinical literature matching Quercetin and "Reduces URI incidence in athletes". Filter by RCT, meta-analysis, or year on the results page.

Discussion

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