Quercetin Reference

Plain English

What it is

Quercetin is a natural plant compound (a flavonoid) found in foods like onions and apples, and it is sold over the counter as a dietary supplement. It is not approved by the FDA as a drug to treat or prevent any condition.

What people use it for

In the anti-aging community, quercetin is best known as the supplement paired with a prescription cancer drug called dasatinib in an experimental combination meant to clear out worn-out (senescent) cells. Some people also use it on its own hoping for general longevity and health benefits.

What the science shows

In people, quercetin has only been studied as the partner ingredient alongside dasatinib in a couple of very small, early pilot studies, one in a lung-scarring disease and one in diabetic kidney disease, each with only a handful of participants. Those researchers themselves called the work first-in-human and preliminary and said larger trials are needed. There is no large human trial showing quercetin on its own slows aging or treats any condition, and the body absorbs only a small fraction of it from the gut.

The catch

Because it is sold as a supplement, quercetin is not held to drug-level testing, and its supposed longevity benefits in humans are largely unproven. The senolytic results people cite come from pairing it with dasatinib, a powerful prescription leukemia chemotherapy drug that carries serious risks, not from quercetin alone, so this is an experimental protocol and not a casual supplement routine.

Reference summary

Quercetin's role in the senolytic context is documented through the Justice 2019 EBioMedicine IPF pilot and Hickson 2019 EBioMedicine diabetic kidney disease pilot - both used quercetin as the dasatinib-partner senolytic agent in a D+Q combination. Quercetin's bioavailability as an oral flavonoid is limited (single-digit-percent oral absorption typical), which informed the rationale for combining it with dasatinib rather than using it alone. There is no large-scale human outcome trial of quercetin monotherapy for any indication.

Regulatory and posture

Categories

Longevity

Aliases

3,3',4',5,7-pentahydroxyflavone, OTC dietary supplement flavonoid, Component of the D+Q senolytic combination

Evidence posture

human - Used in two small senolytic pilots in combination with dasatinib; no large-scale human outcome trial of quercetin monotherapy.

Regulatory status

Over-the-counter dietary supplement in the United States. Not FDA-approved as a drug for any indication. Off-label senolytic use in combination with dasatinib (D+Q) is investigational.

Content review status

research reference

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• Protocol builder overview - Public overview of the Pro protocol builder.