Quercetin

A natural senolytic with anti-cancer and anti-inflammatory properties.

What it is

Quercetin is a flavonoid found in onions, apples, and capers. It has emerged as one of the leading senolytic compounds — agents that selectively clear senescent ("zombie") cells that accumulate during illness and contribute to chronic inflammation.

Why it matters

Senescent cells secrete a cocktail of inflammatory signals (the SASP — Senescence-Associated Secretory Phenotype) that sustain chronic inflammation and facilitate tumour progression. Quercetin selectively removes them. It also inhibits multiple cancer-related kinases, acts as a potent antioxidant, and has direct anti-proliferative effects across several cancer lines.

The evidence

Stanford and Mayo Clinic research established quercetin's senolytic activity. Combined with dasatinib (prescription), quercetin is the most studied senolytic regimen. As a standalone, quercetin at 500–1000mg daily shows significant anti-inflammatory effects in human trials. Fat-soluble — absorption requires dietary fat.

This information is for educational purposes and does not constitute medical advice. Always discuss supplement use with your care team, particularly if you are undergoing active cancer treatment.

Dosing

500–1000mg daily with food containing fat. For senolytic cycling: 1000mg for 2–3 consecutive days per month, ideally combined with fisetin. EGCG may enhance absorption. Quercetin phytosome (Quercefit) has superior bioavailability.

Cautions

Fat-soluble — poor absorption without dietary fat. Mild blood-thinning effect. May interact with certain antibiotics (fluoroquinolones) and immunosuppressants. Separate from iron supplements (reduces iron absorption).