Fisetin: Benefits, Dosage, Forms & Research

What the Research Says

Fisetin's senolytic properties were established by Yousefzadeh et al. (2018) at the Mayo Clinic, who showed it was the most effective of 10 flavonoids tested at clearing senescent cells both in vitro and in vivo. The late-life lifespan extension in mice was particularly striking because it demonstrated benefit even when treatment began at advanced age. Currais et al. (2014) showed neuroprotective effects in Alzheimer's mouse models. The Mayo Clinic AFFIRM trial is testing fisetin in elderly women with frailty markers. Kirkland and colleagues have pioneered the senolytic field and consider fisetin among the most promising candidates alongside dasatinib+quercetin. The main limitation is poor oral bioavailability due to low water solubility, which liposomal formulations may address.

Benefits of Fisetin

• Senolytic activity — Yousefzadeh et al. (2018) screened 10 flavonoids and identified fisetin as the most potent natural senolytic, selectively killing senescent cells while sparing healthy cells in both human and mouse tissues
• Lifespan extension — in the same study, fisetin administered to 85-week-old mice (equivalent to ~75 human years) extended median remaining lifespan by approximately 10% and reduced senescence biomarkers in multiple tissues
• Anti-inflammatory — fisetin reduces SASP factors (IL-6, IL-8, MCP-1, TNF-α) secreted by senescent cells, which drive age-related chronic inflammation and tissue dysfunction
• Neuroprotection — preclinical studies show fisetin maintains cognitive function in Alzheimer's models by reducing neuroinflammation, oxidative stress, and amyloid-beta pathology (Currais et al., 2014)
• Antioxidant — fisetin directly scavenges reactive oxygen species and upregulates endogenous antioxidant enzymes including glutathione, catalase, and superoxide dismutase

Side Effects and Safety

Safety profile: Generally Safe

Potential Side Effects

• Generally well-tolerated at standard doses
• Mild GI discomfort at higher doses
• Limited long-term human safety data
• Theoretical concern about clearing beneficial senescent cells needed for wound healing

Drug & Supplement Interactions

• Blood thinners — fisetin may have mild antiplatelet activity; use caution with anticoagulants
• Chemotherapy — senolytics may interact with cancer treatment protocols; consult oncologist
• CYP enzyme substrates — fisetin may modestly inhibit CYP3A4 and CYP1A2