Fisetin

non-nutrient/non-botanical

What is it

Fisetin is a flavonol polyphenol found in fruits and vegetables including strawberries, apples, persimmons, grapes, and onions. It has gained attention as a senolytic compound under investigation for its potential to selectively clear senescent cells associated with aging.

How it works

Fisetin's most discussed property is its senolytic activity, which refers to its ability to selectively induce apoptosis in senescent (aging, dysfunctional) cells while sparing healthy cells. Senescent cells accumulate with age and contribute to chronic inflammation, tissue dysfunction, and age-related disease through their secretion of inflammatory cytokines (the senescence-associated secretory phenotype, or SASP). Research suggests fisetin works as an antioxidant, scavenging reactive oxygen species and chelating metals. It modulates several signaling pathways including PI3K/AKT/mTOR and Nrf2, with downstream effects on cell survival, autophagy, and antioxidant defenses. Fisetin also has anti-inflammatory effects mediated by NF-kB inhibition. Preclinical animal studies show fisetin can reduce senescent cell burden, improve healthspan markers, and extend median lifespan in mice. Human clinical trials are ongoing but very limited. Bioavailability is poor (typical absorption under 5%); enhanced formulations have been developed to improve plasma levels.

Evidence for 5 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Antioxidant capacity

Grade C

Moderate evidence

Fisetin demonstrates significant antioxidant activity in laboratory and animal studies. Human evidence for clinical effects is limited.

Inflammation

Grade D

Mixed evidence

Preclinical studies show anti-inflammatory effects; human evidence is limited.

Senescent cell clearance (anti-aging)

Grade F

Limited evidence

Strong preclinical evidence for senolytic activity in animal studies. Human clinical trials are ongoing but no published RCTs have yet demonstrated clinical benefits.

Cognitive function

Grade F

Limited evidence

Animal studies suggest neuroprotective effects with potential benefits for cognition and stroke recovery. Human evidence is essentially absent.

Cancer prevention

Grade F

Limited evidence

Preclinical evidence for anticancer activity is substantial but human clinical data are lacking.

3 commercial forms

Standard fisetin extract

Poor oral absorption (under 5%); high doses needed for systemic effects.

Common supplement form. Pure fisetin or extracts standardized to fisetin content.

Liposomal or phospholipid fisetin

Marketed for improved absorption; clinical evidence specific to enhanced forms is limited.

Premium formulations aiming to overcome bioavailability limitations.

Fisetin with quercetin (senolytic combination)

Combined senolytic activity; both compounds have similar mechanisms.

Used in some senolytic research protocols.

Dosage

There is no established RDA. Most preclinical research uses very high doses (e.g., 100 mg/kg in mice). Human supplement doses range from 100-500 mg per day for general use, and intermittent high-dose protocols (e.g., 1500-2000 mg per day for 2 days) have been used in senolytic research. Optimal human dosing remains unclear.

When and how to take it

For general antioxidant use, fisetin can be taken daily with food (its absorption improves with dietary fat). For intermittent senolytic protocols, high doses are typically taken for 2 consecutive days then paused for several weeks. Consistent guidance on optimal timing in humans is still developing.

Food sources

Food	Amount	%DV
Strawberries (1 cup)	approx 5-7 mg fisetin (highest dietary source)	—
Apple (1 medium, with skin)	approx 1-3 mg fisetin	—
Persimmon (1 medium)	approx 1-2 mg fisetin	—
Grapes (1 cup)	approx 1 mg fisetin	—
Onions (1 cup)	approx 1 mg fisetin	—

Safety

Fisetin is generally well tolerated at typical doses. Side effects are uncommon and include mild gastrointestinal upset, headache, or rarely allergic reactions. Long-term safety at higher doses used in senolytic protocols has not been well characterized in humans.

Who should be cautious

Avoid in pregnancy and breastfeeding due to insufficient safety data. People taking anticoagulants or scheduled for surgery should consult a clinician. People undergoing cancer treatment should consult their oncologist. People with allergies to the source foods (strawberries, etc.) should be cautious. High-dose senolytic protocols should be discussed with a clinician familiar with their use.

Interactions

Fisetin may have mild antiplatelet effects and could theoretically increase bleeding risk with anticoagulants. It may inhibit certain CYP450 enzymes, potentially affecting medications cleared by these pathways. Concurrent use with chemotherapy or radiation is being investigated; potential effects on cancer treatment outcomes are unclear.

Frequently asked questions

What are senolytics?⌄

Senolytics are compounds that selectively kill senescent cells, which are aging dysfunctional cells that accumulate with time. Fisetin is one of the most-studied natural senolytic compounds.

Will fisetin make me live longer?⌄

In mice, fisetin extends median lifespan and improves healthspan. In humans, clinical trials are still in early stages. There is no evidence yet that fisetin extends human lifespan.

What dose of fisetin should I take?⌄

General use doses range from 100-500 mg daily. Some senolytic protocols use very high doses (1500-2000 mg per day) for 2 days every few weeks. Consult a clinician before high-dose protocols.

Should I take fisetin daily or intermittently?⌄

For general antioxidant use, daily moderate doses are common. Senolytic protocols use high doses intermittently. Optimal regimens for human health benefits are still being studied.

Can I get enough fisetin from food?⌄

Strawberries are the highest food source but provide only several milligrams per cup. Achieving supplement-level doses through food alone is impractical.

References

PubChem: Fisetin — PubChem link
Wikidata: Fisetin — Wikidata link

Track Fisetin with Pilora

Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.

Coming to App Store

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you're pregnant, breastfeeding, on medications, or managing a chronic condition.