The NIA Interventions Testing Program shows that fisetin does not extend life in mice

Researchers tested fisetin, a plant chemical sold in some supplements, in genetically diverse mice. They gave the mice different doses and compared them with mice that did not receive fisetin. The treatment did not extend the mice’s lives. This was a mouse study, so the result does not directly apply to humans.

What this means for you: There is no good reason to buy fisetin for life extension based on this study. It might still have other effects, but this test found no lifespan benefit in mice.