Fisetin Reference

Plain English

What it is

Fisetin is a natural plant flavonoid, a coloring compound found in fruits and vegetables such as strawberries. In the United States it is sold over the counter as a dietary supplement, and it is not approved by the FDA as a drug for any condition.

What people use it for

In the longevity and healthspan community, people take it as a senolytic, hoping it clears out senescent cells (aged, worn-out cells that build up over time and are linked to aging). The aim is to slow aspects of aging, but this anti-aging use is not a proven medical treatment.

What the science shows

The most striking results are in mice: fisetin was the most potent senolytic of the flavonoids tested, it lowered markers of aged cells in tissues, and it modestly extended lifespan in older mice. In people the picture is still open. A Phase 2 placebo-controlled trial in older adults, called AFFIRM-LITE, is enrolling but has not reported results, so longevity benefits in humans have not been shown.

The catch

The encouraging aging findings come almost entirely from animals, and the human longevity payoff is unproven. Because it is sold as a supplement rather than a regulated drug, quality and how much active compound is actually in a product can vary from one brand to another.

Reference summary

Yousefzadeh 2018 EBioMedicine reported senolytic activity and modest lifespan extension in mouse models. Human outcome data are not yet available; AFFIRM-LITE is the registered Phase 2 trial in older adults.

Regulatory and posture

Categories

Longevity

Aliases

3,3',4',7-tetrahydroxyflavone, Senolytic flavonoid (OTC dietary supplement)

Evidence posture

preclinical - Mostly animal data. Human outcome trials have not reported.

Regulatory status

Over-the-counter dietary supplement in the United States. Not FDA-approved as a drug for any indication. The AFFIRM-LITE Phase 2 trial (NCT03675724) is enrolling but has not reported outcome data.

Content review status

research reference