Fisetin dosage and evidence

What is Fisetin?

How does Fisetin work?

It pushes worn-out cells to die off. That cuts the swelling signals those cells give off.

What have studies in people found about Fisetin?

There are no results in people yet. The mouse results disagree with each other.

• AFFIRM-LITE (NCT03675724): a Mayo Clinic study of frailty and swelling in older adults. No results are posted yet.
• In mice, 2018: one study found longer average and top lifespan.
• In mice, 2024: the US ageing test program found fisetin did not really change lifespan in males or females at the doses used.

What this does not tell you: Until the frailty studies report, every claim about fisetin and human ageing is waiting. A fight between mouse studies is not a reason to guess a human dose.

What do people who took Fisetin report?

This is what real people say happened to them, good and bad. Nobody measured it. A report cannot tell a real effect from the lift people get just from expecting it to work, from a diet or training change made at the same time, or from what was really in the vial. We still put it near the top. It is the next best thing to a study in people: what happens when real people use it, including what goes wrong.

• Used in short pulses rather than daily, which is the most consistent thing about it. People describe several consecutive days at high intake, commonly from several hundred milligrams up to well over a gram a day, then weeks with nothing.
• It is almost never taken alone. Quercetin is the usual companion, often with curcumin and a pepper extract, dissolved in oil, all on the assumption that absorption is the limiting factor. That stacking means no self-report separates it from the other compounds.
• That it does not dissolve well and the body absorbs little of it is treated as the central unsolved problem, and choice of brand is discussed as though it were a meaningful variable.
• Adverse reports during cycles include shivering without a fever, and marked overstimulation where a liposomal quercetin preparation was taken alongside it. A separate strand of discussion is that these flavonoids slow caffeine clearance, which people offer as the explanation for feeling wired.
• People describe self-imposed precautions afterwards, such as avoiding heavy lifting for a week over bleeding concerns. Those are decisions taken from reasoning rather than from anything observed.
• Concrete benefit reports are conspicuously absent. What people describe is having completed a protocol, not an outcome they could point to.

Sources: Senolytics forum threads on LongeCity, including completed cycle write-ups and a thread on how the body breaks down caffeine, found by site-restricted search, September 2026. Nothing above is attributed to any specific post and no post is reproduced.

The evidence, in charts

The studies we cite

• Study in people2026
  Alleviation by fisetin of frailty, inflammation, and related measures in older adults (AFFIRM-LITE)

  No results yet. This is a Mayo Clinic trial of fisetin in older adults, looking at frailty and inflammation. It is enrolling by invitation and has not reported anything. Every claim currently made about fisetin and human ageing is waiting on studies like this one to arrive.

  Mayo Clinic Phase 2 trial of fisetin in older adults; enrolling by invitation, results pending.

  NCT03675724 ClinicalTrials.gov
• Animal study2018
  Fisetin is a senotherapeutic that extends health and lifespan

  In mice: of 10 plant compounds tested, fisetin was the best at clearing worn-out cells. Given late in life, it made mice live longer, both on average and at the top end.

  Most potent senolytic among 10 flavonoids; late-life fisetin reduced senescence markers and extended median and maximum lifespan in mice.

  PMID 30279143 EBioMedicine
• Animal study2024
  Astaxanthin and meclizine extend lifespan in UM-HET3 male mice; fisetin and other agents do not significantly affect lifespan

  In mice: the US government's ageing test program gave fisetin to mice. It did not really change how long males or females lived at the doses used.

  NIA Interventions Testing Program: fisetin did not significantly affect lifespan in either sex at the doses used.

  PMID 38041783 GeroScience