Supplement
Fisetin
Fisetin is a plant flavonoid that became the most accessible face of senolytics — drugs intended to clear senescent 'zombie' cells — after striking mouse results from the Mayo-linked research groups. It is cheap and widely sold, and it sits at an unusual moment: the animal case is genuinely interesting and the decisive human trials are underway but unreported.
Quick verdict
In aged mice, fisetin reduced senescence markers and extended late-life health and lifespan. No completed randomised human trial has yet shown any benefit; several — in breast cancer survivors, frail older adults and other groups — are in progress. A rational buyer would wait for them.
The assessment
Claim by claim
Each claim is graded on its own evidence. A grade for one claim says nothing about the others.
| Claim | What was measured | Evidence |
|---|---|---|
| Clears senescent cells and extends lifespan | Lifespan | Preclinical |
| Improves function or health outcomes in humans | Disease outcome | Insufficient |
Clears senescent cells and extends lifespan
Preclinical onlyOutcome measured: Lifespan — Death from any cause was measured.
In mice, this claim has real support: fisetin given to aged animals reduced senescence markers across tissues and extended remaining lifespan and healthspan. It is among the more striking senolytic results in animals — and remains entirely an animal result.
Why this grade — the appraisal in full
Evidence comes from animals, cell cultures or modelling. No human trial has tested this claim. Animal lifespan results do not establish human benefit.
- Human evidence. No human study has tested this claim. Evidence comes from 1 animal study and 0 laboratory studies.
- Translation to humans. Results in animals frequently fail to reproduce in people. A lifespan effect in mice is not evidence of a lifespan effect in humans.
Limitations. Mouse data from a network of collaborating labs; senolytic dosing in humans is intermittent and unvalidated.
| Study | Design | Population | Finding |
|---|---|---|---|
| [1]Fisetin is a senotherapeutic that extends health and lifespanEBioMedicine · 2018 · PMID 30279143 | Animal studyAnimal | Size not recorded | Supports the claimAged mice: reduced senescence markers and extended health and lifespan with fisetin. |
Improves function or health outcomes in humans
Insufficient evidenceOutcome measured: Disease outcome — A diagnosed condition or clinical event was measured.
No completed randomised trial has reported. The trials that will answer this are registered and running — a phase II in postmenopausal breast cancer survivors with reduced physical function among them — which makes fisetin one of the few supplements where 'wait' has a specific, checkable meaning.
Why this grade — the appraisal in full
Too little credible research exists to judge the claim either way.
- Available research. No usable studies are linked to this claim.
Limitations. The absence is temporary by design: registered trials are in progress and this grade should be expected to change.
Human evidence
0 studies in people.
No human study is currently linked to any claim on this page.
Animal and laboratory evidence
Shown separately, and never used to support a human claim.
- Animal study
Before anything else
Safety and interactions
Generally unremarkable at supplement doses in short human studies; the intermittent high-dose senolytic protocols copied from trial designs (20 mg/kg) have no published controlled safety data.
The ledger
Grade history
22 August 2026
First published appraisal of this claim. Study links added: PMID 30279143.
22 August 2026
First published appraisal of this claim.
Falsifiability
What would change our view
The first completed randomised trials — including TROFFi in breast cancer survivors — will move this page in whichever direction they report.
Check everything
Sources
Every citation links to its PubMed record. Bibliographic details are retrieved from PubMed, not written by us.
- [1]Fisetin is a senotherapeutic that extends health and lifespan Yousefzadeh MJ et al.. EBioMedicine. 2018. PMID 30279143 · doi:10.1016/j.ebiom.2018.09.015