Fisetin
Also known as: 3,3',4',7-tetrahydroxyflavone, fisetin flavonoid, strawberry flavonoid
Effective Dosage
No established dose from provided studies for general use; 20 mg/kg/day used in one clinical trial design
What the Science Says
Fisetin is a naturally occurring flavonoid found in strawberries, apples, and other fruits. It is being studied primarily as a 'senolytic' agent — meaning it may help clear out damaged, aging cells (called senescent cells) that accumulate in the body and drive inflammation. Most of the promising evidence comes from animal studies and lab work; human clinical trials are still underway, with one major trial testing 20 mg/kg/day in breast cancer survivors to see if it can improve physical function after chemotherapy.
What It Doesn't Do
Not proven to improve liver function in humans — one RCT found no significant effect. Not proven to extend lifespan or reverse aging in people. No solid human evidence yet for neuroprotection, heart protection, or cancer prevention despite pre-clinical hype. Standard supplement doses (typically 100–500 mg) have not been tested for most marketed benefits.
Evidence-Based Benefits
Fisetin is a naturally occurring flavonoid found in strawberries, apples, and other fruits. It is being studied primarily as a 'senolytic' agent — meaning it may help clear out damaged, aging cells (called senescent cells) that accumulate in the body and drive inflammation. Most of the promising evidence comes from animal studies and lab work; human clinical trials are still underway, with one major trial testing 20 mg/kg/day in breast cancer survivors to see if it can improve physical function after chemotherapy.
Weak EvidenceEffective at: No established dose from provided studies for general use; 20 mg/kg/day used in one clinical trial design
Source: auto-research
Absorption & Bioavailability
Poor in standard form. One human pharmacokinetic study found a novel encapsulated formulation (FF-20) delivered 26.9x more fisetin into the bloodstream than unformulated fisetin. Animal data also suggests fisetin has relatively high absorption among flavonoids, but standard oral fisetin supplements likely have very low bioavailability without special formulation.
Red Flags to Watch For
- Most benefits are based on pre-clinical (cell and animal) studies — very few completed human trials exist
- Standard supplement doses have not been validated in human trials; the clinical trial dose of 20 mg/kg/day is far higher than typical products
- Bioavailability of unformulated fisetin is very poor, meaning most products on shelves may deliver little active compound
- One completed RCT (liver function) showed no significant benefit, suggesting pre-clinical results don't always translate to humans
- 87 registered supplement products exist despite minimal human evidence — marketing is far ahead of the science
Products Containing Fisetin
See how Fisetin is used in these analyzed products:
Research Sources
- PubMed
- NIH DSLD
This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-04-08