Quercetin

What it is

Quercetin is a flavonol abundant in onions, apples, capers, and many berries. As a supplement it’s commonly paired with dasatinib in senolytic protocols (D+Q), targeting BCL-xL and PI3K survival pathways in senescent cells.

Why it’s of interest

In senolytic combinations, quercetin clears senescent cells in adipose and other tissues in mice, improving multiple healthspan endpoints. As a solo over-the-counter supplement, its bioavailability is poor and the human longevity evidence is thin.

Other uses

• Marketed as an immune-support supplement (limited RCT support).
• Used as a zinc ionophore in some COVID-era off-label protocols (no endorsement implied).
• Cardiometabolic effects (modest reductions in blood pressure in some meta-analyses).

Safety

Generally well-tolerated at typical supplement doses (500–1000 mg/day). Concerns at high doses include nephrotoxicity (case reports) and drug-interaction potential via CYP3A4 inhibition.

Related entries

Senolytics, Fisetin, Cellular senescence.