Fisetin

Snapshot

Indications	Contraindications
Healthy aging¹ Chronic low-grade inflammation¹ Colorectal cancer inflammatory markers² Post-coronavirus disease symptoms³	Bleeding disorders⁴ Anticoagulant or antiplatelet use⁴ Pregnancy or nursing⁴

Fisetin is a flavonoid found in strawberries, apples, persimmons, onions, and cucumbers, and concentrated supplements are sold⁵. People take it for its senolytic action, the clearing of aged non-dividing cells, and for anti-inflammatory and antioxidant effects, shown mainly in preclinical work. The uses that follow are healthy aging and frailty in older adults, brain health, and cardiovascular protection.

Human research is limited to about six small trials, covering colorectal cancer, ischemic stroke, Gulf War illness, obesity with exercise training, and absorption. Completed trials show limited, mixed results, with some favorable inflammatory changes and others without clear benefit. Unformulated fisetin is poorly absorbed, and a hydrogel formulation raised plasma levels in healthy volunteers. A 2024 cross-sectional survey of patients at a post-coronavirus disease 2019 clinic found fisetin among interventions patients rated helpful; no controlled trial has tested it. Products listing fisetin are mostly capsules, with 87 in the label database; see Form comparison.

No human research has established the safety of long-term supplemental use, and possible carcinogenic effects have been identified without being characterized in humans⁵. Per United States product labels, anticoagulant or antiplatelet therapy and bleeding disorders call for consulting a healthcare provider before use⁴.

Last updated October 16, 2026. Read how we make monographs.

In the full monograph

46 sources, 32 studies

When to useThe situations practitioners use it for, each with the reason and the study behind it.
SafetyWho should avoid it, who needs extra care, and the side effects reported in studies.
InteractionsThe medicines and supplements it interacts with, the effect of each, and what labeling says to watch.
Protocol notesThe doses used in studies, how and when they were taken, and how the forms on the market compare.
How it worksWhat it is and how it works in the body, in plain terms.
Published studiesThe studies behind each use, popular claims checked against them, and trials still under way.
Word of mouthWhat patients and practitioners report online, kept separate from the clinical evidence.
Clinical perspectiveA closing read of where the evidence is solid, where it is thin, and what has not been studied.

Snapshot

In the full monograph

Sources