What Is Fisetin?
Fisetin (3,3',4',7-tetrahydroxyflavone) is a naturally occurring flavonoid found in strawberries, apples, persimmons, grapes, onions, and cucumbers. In longevity research, it is classified as a senolytic—a compound that selectively induces apoptosis (programmed cell death) in senescent cells while leaving healthy cells unharmed.
Senescent cells are cells that have permanently exited the cell cycle but resist apoptosis. They accumulate with age, injury, and chronic disease, and secrete a cocktail of pro-inflammatory cytokines, matrix metalloproteinases, and growth factors collectively called the Senescence-Associated Secretory Phenotype (SASP). The SASP drives chronic low-grade inflammation ("inflammaging"), tissue dysfunction, and accelerated aging in surrounding cells.
The Senolytic Mechanism
Fisetin's senolytic activity operates through:
- PI3K/AKT pathway inhibition: Senescent cells rely on the PI3K/AKT survival pathway for their resistance to apoptosis. Fisetin inhibits this pathway selectively in senescent cells.
- BCL-2 family inhibition: Fisetin inhibits anti-apoptotic BCL-2 family proteins (BCL-2, BCL-XL) that senescent cells upregulate. This is similar to the mechanism of dasatinib/navitoclax—pharmaceutical senolytics.
- SASP suppression: Even in cells that survive, fisetin reduces NF-κB-driven SASP secretion, lowering inflammatory cytokine output.
- Antioxidant effects: Independent of senolytics, fisetin is a potent antioxidant that reduces oxidative stress contributing to senescence induction.
A 2018 landmark study by Yousefzadeh et al. (EBioMedicine) from the Mayo Clinic/Buck Institute tested 10 natural compounds for senolytic activity in aged mouse tissues. Fisetin ranked #1—eliminating up to 50–60% of senescent cells in adipose tissue, liver, and brain compared to vehicle controls. Fisetin-treated mice showed improved physical function and healthspan measures. This study is the scientific basis for fisetin's prominence in longevity circles.
Fisetin vs Other Senolytics
| Senolytic | Type | Potency | Human Data | Availability India |
|---|---|---|---|---|
| Fisetin | Natural flavonoid | Highest natural | Phase I/II trials ongoing | Online import |
| Quercetin | Natural flavonoid | Moderate | Used in D+Q trials | Widely available |
| Dasatinib + Quercetin (D+Q) | Drug + supplement | Very high | Phase II completed (DM, IPF) | Dasatinib Rx only |
| Navitoclax | Pharmaceutical | Very high | Clinical trials | Investigational only |
| Spermidine | Polyamine | Indirect (autophagy) | APEX trial positive | Food/supplement |
Dosing Protocols
Two distinct protocols are used:
- Senolytic burst protocol (anti-aging primary use): 20 mg/kg body weight per day × 2 consecutive days per month. For a 65 kg person: 1300 mg/day for 2 days each month. Take with fat-containing food for maximum absorption.
- Daily maintenance (anti-inflammatory / antioxidant): 100–500 mg/day. This does not achieve peak senolytic concentrations but provides ongoing anti-inflammatory and neuroprotective benefits.
The burst protocol is preferred for senolytic purposes based on the Mayo Clinic's human trial protocol (Sundesara et al. 2022: 20 mg/kg × 2 days in patients with diabetic kidney disease).
Fisetin is a fat-soluble flavonoid with variable oral bioavailability. Taking with a meal high in olive oil, avocado, or full-fat yogurt significantly improves absorption. Some formulations use liposomal delivery or piperine (black pepper extract) to further enhance uptake. Avoid taking on an empty stomach for the senolytic protocol to maximise plasma concentrations.
Safety Profile
- No serious adverse events reported in any human trial to date
- High-dose (20 mg/kg) protocol is well-tolerated in Phase I/II trials
- Mild GI discomfort at very high doses reported in some individuals
- Potential interaction with anticoagulants (mild platelet inhibition); caution with warfarin
- May inhibit CYP3A4 at very high doses—separate from other medications by 2+ hours
- Theoretical concern about suppressing senescence in pre-cancerous cells, though this has not been observed clinically
Frequently Asked Questions
What is the fisetin senolytic protocol?
The most studied protocol is 20 mg/kg/day for 2 consecutive days per month, based on Mayo Clinic human trials. For a 65 kg person, this is 1300 mg/day for 2 days. Take with fat-containing food. The monthly interval is based on the time needed for senescent cells to re-accumulate after clearance. Some biohackers use quarterly protocols (every 3 months) for lower-frequency intervention. Daily low-dose (100–500 mg) is a separate anti-inflammatory protocol.
Fisetin vs quercetin – which is the better senolytic?
Fisetin is the stronger standalone senolytic based on the Mayo Clinic comparison study. Quercetin shows moderate senolytic activity alone but is extremely potent when combined with dasatinib (D+Q)—the most-studied senolytic combination in humans (requires prescription dasatinib). For supplementation without a prescription, fisetin is the preferred choice. Both can be combined at lower doses for additive effect.
What is the fisetin dosage for anti-aging in India?
Senolytic protocol: 20 mg/kg × 2 days per month. A 60 kg person takes 1200 mg/day for 2 days. Daily antioxidant maintenance: 100–500 mg/day. Both require fat-containing food for optimal absorption. In India, fisetin supplements are primarily available via online import; plan 2–3 weeks for delivery. Budget approximately ₹1,500–3,000/month for quality fisetin (the 2 monthly burst days are relatively inexpensive at this dose).
Where can I buy fisetin in India?
Fisetin is not commonly available in Indian pharmacies. Online options include: iHerb (ships to India), Amazon India (select vendors), and specialty supplement importers. Look for products standardised from Cotinus coggygria (smoke tree) or Rhus succedanea—the richest botanical sources. Confirm the stated mg is fisetin content, not plant extract weight. Nootropics Depot, Double Wood, and Life Extension are well-regarded brands for quality assurance.