Fisetin
A flavonoid found in strawberries with the most potent senolytic activity among all tested compounds. Selectively eliminates senescent cells that accumulate with age and drive systemic inflammation — the SASP effect.
Reviewed & fact-checked by
Dr. Jane Smith, MD, PhDChief Medical Reviewer · Last updated: March 1, 2026
Medical Disclaimer: The information on this page is for educational and research purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment.
Senolytics: Why It Matters
As we age, tissues accumulate 'zombie cells' — senescent cells that have stopped dividing but haven't died. They actively secrete pro-inflammatory cytokines (the Senescence-Associated Secretory Phenotype, or SASP), damaging surrounding tissues and accelerating systemic ageing. []
Fisetin as a Senolytic
In a Mayo Clinic 2018 study, Fisetin demonstrated the highest senolytic activity among 10 tested flavonoids. It selectively induces apoptosis in senescent cells by suppressing BCL-2/BCL-XL anti-apoptotic proteins, without affecting healthy cells. []
The Pulse Dosing Protocol
Senolytics are effective precisely because of pulse dosing (2 consecutive days, once per month) for two reasons:
- Senescent cells accumulate slowly — monthly clearance is sufficient
- A high single-day dose creates the concentration needed to overcome the anti-apoptotic defences of senescent cells
Stacking Interactions
How Fisetin interacts with other compounds
Both taken with fat for bioavailability. Can be co-administered on pulse dosing days.
Safety Profile — Tier A
Well-tolerated — strong human evidence
Contraindications
- ●Blood-thinning medications (fisetin inhibits platelet aggregation)
- ●Pregnancy — insufficient safety data
Side Effects
- ●Generally well-tolerated
- ●Loose stools at very high doses