Know2eat

Fisetin

Isolated Compounds

What fisetin may help with

Ranked by how strong the human evidence is — best supported first.

Best supportedCognitive functionNot enough evidence· 4 sources

Then, in order

About Fisetin

A flavonol found in strawberries, apples and onions, sold as a purified isolate usually extracted from the smoke tree. It is marketed on the basis of senolytic activity — the selective clearance of senescent cells.

Fisetin is the most heavily promoted of the so-called senolytics, on the strength of a 2018 mouse study reporting extended lifespan and reduced senescent cell burden. What is being sold to humans is that mouse study plus a set of clinical trials that are still in progress. The trials use short intermittent high doses — a "hit and run" schedule of grams per day for a couple of days — which is nothing like the daily low-dose capsule most people buy. Oral bioavailability is very poor and the compound is cleared quickly, which is why the trial protocols use such large amounts. Nobody currently knows whether fisetin does anything measurable in a person.

Sold as
Capsule, Liposomal capsule, Powder
Standardised to
Percentage fisetin, typically 98% from Cotinus coggygria — a product without this marker may not resemble what was studied.
Also known as
3,3′,4′,7-tetrahydroxyflavone, Senolytic flavonoid

Regulation: Sold as a dietary supplement in the US with no pre-market efficacy review, while being simultaneously investigated as an experimental drug in registered clinical trials. Nothing has been approved.

What the research used

The amounts, forms and durations published trials of Fisetin actually administered.

These are the amounts published trials administered — not a recommendation, and not a dose to copy. Trial participants were screened, supervised and given a characterised preparation. What is in a retail bottle is frequently not what was studied, and the amount that suits one person is not general advice.

  • Studied for Registered senolytic trials

    20 mg

    Not enough

    Per kilogram of body weight, daily for two consecutive days per month · Several monthly cycles

    The intermittent protocol used in ongoing trials, which for an average adult is one to two grams per day for two days. Results are not yet published, and this is not how retail capsules are taken.

  • Studied for Retail supplement use

    100–500 mg

    Not enough

    Capsule, daily

    What products contain. There is no trial of daily low-dose fisetin, so this dose has no evidential basis whatsoever.

This is general information about food, not medical advice. It cannot diagnose, treat or replace guidance from a clinician who knows your history.

When it was taken

Each window says whether a trial compared it against an alternative, or whether it is convention and pharmacology. Most timing advice is the second kind.

None of the timings below were directly compared in a trial. They reflect how the research happened to dose, or what the pharmacology implies — which is not the same as a timing being better.

  • With food

    Not enough

    Taken with fat because fisetin is poorly water-soluble, and trials administer it with food. Whether it matters has not been tested.

    Timing was not directly compared. This reflects convention or how the compound behaves in the body, not a trial showing this window works better.

The evidence in depth

Best supported: Not enough

What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how promising the supplement sounds. How we rate evidence.

Cognitive function

Brain & Cognitive Health
Not enough evidence

Neuroprotective effects in rodent models have not been followed by human cognitive trials. There is nothing to report in people.

Not enough evidence. Not enough human research to say anything useful yet.

View the 4 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

DNA and cellular integrity

Cellular Health
Not enough evidence

The senolytic evidence is entirely from cells and mice. Human trials are under way and have not reported results, so any claim about clearing senescent cells in people is speculation ahead of data.

What may be going on: Fisetin appears to selectively induce apoptosis in senescent cells in culture, in part through inhibition of survival pathways those cells depend on.

Not enough evidence. Not enough human research to say anything useful yet.

View the 1 source

Deep research mode adds each paper’s own conclusion and stated limitations.

Inflammatory markers

Inflammation
Not enough evidence

Reductions in inflammatory markers have been reported in animals. Human data are not yet available in published form.

Not enough evidence. Not enough human research to say anything useful yet.

View the 4 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

Things to know

Interactions, contraindications and dose limits, most serious first. Concentrated extracts interact with medication in ways the whole plant does not, so this section carries more weight here than it does on a food page.

  • Worth knowing

    High-dose intermittent protocols are experimental

    The gram-level doses being tested in trials are given under medical supervision with monitoring, for two days at a time. Copying that protocol at home from an unregulated capsule is self-experimentation with a compound whose human safety profile is not established.

  • Interaction

    Flavonol enzyme and transporter inhibition

    Interacts withAnticoagulants, antiplatelet drugs, CYP3A4 substrates

    Fisetin inhibits CYP enzymes and drug transporters in laboratory work, and inhibits platelet aggregation. Interactions with anticoagulants and with drugs cleared by CYP3A4 are plausible and untested in people.

  • Worth knowing

    The evidence is a mouse study

    The entire commercial case rests on one 2018 rodent lifespan paper. Mouse lifespan results in this field have a poor track record of translating, and the compound is being sold years ahead of any human outcome data.

  • Avoid

    No data in pregnancy, breastfeeding or cancer

    Fisetin has cytotoxic properties in cell culture and no human safety data in vulnerable groups. It should not be combined with cancer treatment outside a trial.

In the food catalogue

The whole-food form, where one exists. The evidence for a concentrated extract rarely transfers to the food, or the other way round — these are cross-links, not equivalents.

ApplesContains fisetin among other flavonols.StrawberriesThe richest known food source, though at a small fraction of a…

Evidence ratings on this page: 3 not enough evidence.

Supplements are sold in the US without pre-market review of efficacy or safety. Nothing on this page is a recommendation to take Fisetin, or a dose to follow.