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Fisetin
Bottom line
In our scoring, Fisetin rates weak evidence: the human evidence is thin for clears senescent cells. Our top-scored product is Ultra High Purity Fisetin 500mg (79/100), about $1.47 a day. Bottom line: treat any benefit as unproven. This is our opinion, not medical advice; talk to your clinician before starting.
Fisetin is the poster child for the honest gap between mouse longevity data and human proof.
- Evidence
- Weak Evidence
- Category
- Energy & Performance
- Best form
- 98% standardized fisetin
- Effective dose
- Two regimens: intermittent high-dose (~20 mg/kg, ~1,000-1,500 mg for 2 days, monthly), or daily 100-500 mg
- Lab tested
- 6 of 7 products
- Category
- Energy & Performance
- Best form
- 98% standardized fisetin
- Effective dose
- Two regimens: intermittent high-dose (~20 mg/kg, ~1,000-1,500 mg for 2 days, monthly), or daily 100-500 mg
- Lab tested
- 6 of 7 products
Key takeaways
- →The most potent natural senolytic in a Mayo Clinic screen - it cleared 'zombie' cells and extended mouse lifespan ~10%. That result is real, and it is in mice.
- →No completed human trial has confirmed a longevity or anti-frailty benefit yet. Mayo's human trials use an intermittent high-dose protocol (~20 mg/kg for 2 days, monthly) and are ongoing.
- →Toniiq (500 mg, 98% pure, MCT for absorption) is our Top Pick; ProHealth's pure 250 mg is the Best Value. Skip 'senolytic complex' blends whose '2,000 mg' is a label sum, not pure fisetin.
- →A low-risk, low-cost bet on early science - not a proven anti-aging supplement. It pairs with quercetin, a weaker senolytic we cover separately.
What Is Fisetin?
Fisetin is the poster child for the honest gap between mouse longevity data and human proof. In mice, it is genuinely impressive: Mayo Clinic researchers screened ten flavonoids and found fisetin the most potent natural "senolytic" - a compound that clears senescent, or "zombie," cells that accumulate with age and drive inflammation. Dosed late in life, it extended median and maximum lifespan by around 10% and reduced age-related tissue damage (Yousefzadeh 2018). That is a real, striking finding. The catch, and it is the whole story for scoring, is that no completed human trial has yet shown fisetin does any of this in people. Buy it as an interesting, low-risk bet on early science, not as a proven anti-aging tool.
The senescent-cell idea is legitimate biology. As you age, some cells stop dividing but refuse to die, leaking inflammatory signals that harm the tissue around them. Senolytics like fisetin push those cells to finally undergo programmed death. In animals this improved physical function and healthspan. The appeal of fisetin specifically is that it is a natural flavonoid found in strawberries and apples, cheap, and well tolerated at the doses tested.
Where it stands with people is the honest part. Mayo Clinic is running human trials (the AFFIRM-LITE frailty study and others) using an intermittent "hit-and-run" protocol - roughly 20 mg/kg for two consecutive days, then a long break - the same on-off schedule that worked in mice. Those trials are ongoing and unpublished, so the human efficacy question is genuinely open. It is worth noting that the one class of senolytics with early human data is dasatinib plus quercetin (a different combination), not fisetin. So fisetin is riding real animal data and a plausible mechanism into an unproven human promise.
Two practical notes if you try it. First, fisetin is poorly absorbed, so products add liposomal delivery or MCT oil, and taking it with a fatty meal helps. Second, watch the labels: several "senolytic complex" products advertise "2,000 mg" that is actually the combined total of fisetin plus quercetin, resveratrol, and other add-ins, not 2,000 mg of pure fisetin. For a clean experiment, favor a pure, 98% standardized fisetin and decide up front whether you are doing the daily low dose or the intermittent high-dose protocol. It pairs naturally with quercetin, a weaker senolytic we cover separately.
Does It Work? The Evidence
How A-F grades workFisetin earns a Weak Evidence rating - human evidence is thin across its claimed uses, the best-supported being clears senescent cells (senolytic activity) (grade B). Each claim is graded individually below.
Clears senescent cells (senolytic activity)
Yousefzadeh et al. 2018 (EBioMedicine): fisetin was the most potent senolytic of 10 flavonoids screened; reduced senescence markers across tissues in mice
Extends healthspan and lifespan
Yousefzadeh 2018: late-life dosing extended median and maximum lifespan ~10% and reduced age-related pathology - in mice, not yet humans
Acts as an antioxidant / anti-inflammatory flavonoid
Consistent with the broader flavonoid literature (fisetin is found in strawberries and apples); general antioxidant activity, not a specific proven clinical outcome
Is well absorbed at standard doses
Fisetin has low oral bioavailability; liposomal delivery (Henschke 2025) and fat/MCT co-administration are used to partly address this
Reduces frailty and inflammation in humans
Mayo Clinic AFFIRM-LITE and related human trials (intermittent ~20 mg/kg protocol) are ongoing and unpublished; no completed trial has confirmed a human benefit
| Grade | Claimed Benefit | Key Studies | Our Verdict |
|---|---|---|---|
| B | Clears senescent cells (senolytic activity) | Yousefzadeh et al. 2018 (EBioMedicine): fisetin was the most potent senolytic of 10 flavonoids screened; reduced senescence markers across tissues in mice | Early Signal |
| C | Extends healthspan and lifespan | Yousefzadeh 2018: late-life dosing extended median and maximum lifespan ~10% and reduced age-related pathology - in mice, not yet humans | Early Signal |
| C | Acts as an antioxidant / anti-inflammatory flavonoid | Consistent with the broader flavonoid literature (fisetin is found in strawberries and apples); general antioxidant activity, not a specific proven clinical outcome | Early Signal |
| D | Is well absorbed at standard doses | Fisetin has low oral bioavailability; liposomal delivery (Henschke 2025) and fat/MCT co-administration are used to partly address this | Conflicted |
| F | Reduces frailty and inflammation in humans | Mayo Clinic AFFIRM-LITE and related human trials (intermittent ~20 mg/kg protocol) are ongoing and unpublished; no completed trial has confirmed a human benefit | Not There Yet |
How to Choose: Forms, Doses & What Matters
Clinical dose: Two regimens: intermittent high-dose (~20 mg/kg, ~1,000-1,500 mg for 2 days, monthly), or daily 100-500 mg
Best forms: 98% standardized fisetin, liposomal or with MCT/fat for absorption (fisetin is poorly absorbed), pure fisetin over label-sum 'senolytic complex' blends
There are two schools of thought. The daily approach is 100-500 mg with a fatty meal (fisetin absorbs poorly without fat). The intermittent 'senolytic' approach mirrors the trials: a high dose (around 20 mg/kg, often 1,000-1,500 mg) for two consecutive days, then a break of a month or a quarter - the on-off pattern that worked in mice. Neither is proven better in humans. Liposomal or MCT-paired products absorb somewhat better. Whichever you choose, pick a pure 98% standardized fisetin so you know your actual dose.
Who Should Take Fisetin?
This suits people who follow longevity science, understand they are betting on strong animal data rather than proven human results, and want a low-cost, well-tolerated experiment. If you already take quercetin for its senolytic angle, fisetin is the more potent cousin and a logical addition. Anyone drawn to the intermittent 'hit-and-run' protocol should read up on the roughly 20 mg/kg, two-days-a-month schedule the trials use, rather than defaulting to a daily capsule.
Who Should Avoid It?
Not for everyone
Side Effects & Safety
Product Scores
7 products scored on dosing accuracy, third-party testing, cost per effective dose, and label transparency.
The Scorecard: 7 Products Compared
Ultra High Purity Fisetin 500mg
Toniiq
$43.99 ÷ 30 days at 500mg/day (1 serving × 500mg)
The cleanest full-dose option: high purity, an absorption aid, and real testing. In our view the best single product for someone who wants a proper fisetin dose without assembling it from small caps.
Prices checked 2026-07-05. Cost shown is per clinically effective daily dose, not per pill.
Pure Fisetin 250mg
ProHealth
$34.95 ÷ 30 days at 500mg/day (2 servings × 250mg)
The value pick for pure fisetin, and the most convenient size if you follow the intermittent high-dose protocol. Take it with fat, since there is no absorption enhancer.
Prices checked 2026-07-05. Cost shown is per clinically effective daily dose, not per pill.
Fisetin 100mg
Nutricost$15.95 ÷ 12 days at 500mg/day (5 servings × 100mg)
A cheap, clean way to buy fisetin, but the 100 mg cap size means a lot of capsules if you want a meaningful dose. Best for low-dose daily users.
Prices checked 2026-07-05. Cost shown is per clinically effective daily dose, not per pill.
Fisetin 100mg
Double Wood
$17.95 ÷ 12 days at 500mg/day (5 servings × 100mg)
A transparent commodity option with published COAs. Like other 100 mg caps, it takes several to reach a meaningful dose.
Prices checked 2026-07-05. Cost shown is per clinically effective daily dose, not per pill.
Liposomal Fisetin 150mg
Renue By Science
$39.95 ÷ 27 days at ~500mg/day (3.3 servings × 150mg)
The absorption-focused option. If fisetin's poor bioavailability is your concern, liposomal delivery is a reasonable answer, though the size of the advantage is not independently established. As of this review the Amazon listing was unavailable - Renue By Science is a direct-first brand that sells this primarily from its own site.
Prices checked 2026-07-05. Cost shown is per clinically effective daily dose, not per pill.
Fisetin with Novusetin 100mg
Doctor's Best$16.99 ÷ 6 days at 500mg/day (5 servings × 100mg)
A recognizable brand using standardized Novusetin fisetin, but the small bottle and 100 mg dose make it a costly way to reach a meaningful amount.
Prices checked 2026-07-05. Cost shown is per clinically effective daily dose, not per pill.
Fisetin Pro Longevity Plus 125mg
ProHealth
$35.95 ÷ 15 days at 500mg/day (4 servings × 125mg)
A combination product where the low fisetin dose and a proprietary absorption blend make it hard to know what you are really getting. In our view a pure, disclosed fisetin plus a fatty meal is the cleaner choice.
Prices checked 2026-07-05. Cost shown is per clinically effective daily dose, not per pill.
Full Comparison
| Category | Ultra High Purity Fisetin 500mg Toniiq | Pure Fisetin 250mg ProHealth | Fisetin 100mg Nutricost | Fisetin 100mg Double Wood | Liposomal Fisetin 150mg Renue By Science | Fisetin with Novusetin 100mg Doctor's Best | Fisetin Pro Longevity Plus 125mg ProHealth |
|---|---|---|---|---|---|---|---|
| Brand Score | 79/100Winner | 77/100 | 74/100 | 72/100 | 70/100 | 66/100 | 58/100 |
| Dosing & Form | 23/25Winner | 21/25 | 18/25 | 18/25 | 19/25 | 16/25 | 15/25 |
| Purity | 18/25Winner | 18/25 | 17/25 | 16/25 | 15/25 | 15/25 | 16/25 |
| Value | 17/25 | 18/25 | 20/25Winner | 18/25 | 15/25 | 12/25 | 12/25 |
| Transparency | 21/25 | 20/25 | 19/25 | 20/25 | 21/25 | 23/25Winner | 15/25 |
| Cost/Day | $1.47 | $1.17Winner | $1.33 | $1.50 | $1.48 | $2.83 | $2.40 |
| Dose/Serving | 500mg | 250mg | 100mg | 100mg | 150mg | 100mg | 125mg |
| Form | Capsule (98% fisetin + MCT oil) | Capsule (pure fisetin) | Capsule (pure fisetin) | Capsule (pure fisetin) | Capsule (liposomal fisetin) | Capsule (Novusetin branded fisetin) | Capsule (125 mg fisetin + proprietary absorption blend) |
| Third-Party Tested | ✓ Yes | ✓ Yes | ✓ Yes | ✓ Yes | ✓ Yes | No | ✓ Yes |
| Proprietary Blend | No | No | No | No | No | No | Yes |
Frequently Asked Questions
Does fisetin actually work for longevity?
In mice, the evidence is genuinely strong: fisetin was the most potent natural senolytic in a Mayo Clinic screen and extended mouse lifespan by about 10%. In humans, no completed trial has yet confirmed a longevity or anti-frailty benefit - Mayo's human trials are ongoing and unpublished. So fisetin is best described as a compound with impressive animal data and an unproven, actively studied human promise. It is a reasonable early-science bet, not an established anti-aging supplement.
What is the fisetin 'Mayo protocol'?
It refers to the intermittent, high-dose 'hit-and-run' schedule used in Mayo Clinic's human trials: roughly 20 mg/kg of body weight (about 1,000-1,500 mg for most adults) taken for two consecutive days, then a long break of a month or a quarter. The logic is that senolytics work by triggering a burst of senescent-cell clearance, so you do not need to dose daily. This differs from the daily 100-500 mg approach most capsules are sized for, and neither is proven superior in humans yet.
Should I take fisetin or quercetin?
They are related flavonoids and are often stacked. Fisetin is the more potent senolytic of the two in lab screens, while quercetin has a broader, longer track record for allergy and antioxidant uses and appears in the one senolytic combination with early human data (dasatinib plus quercetin). If your interest is specifically the senolytic longevity angle, fisetin is the stronger candidate; many people who follow this science take both. See our quercetin scorecard for that side of the comparison.
Why is fisetin so hard to absorb?
Fisetin is a lipophilic (fat-loving) flavonoid with low water solubility, so only a fraction of an oral dose reaches the bloodstream. Products address this with liposomal delivery or by adding MCT oil, and taking fisetin with a fatty meal helps. This poor bioavailability is one reason the human dosing question is still open - it is not always clear how much of a swallowed dose actually does anything.
Are the '2,000 mg' fisetin products a better deal?
Usually not. Many high-number products are 'senolytic complex' blends where the '2,000 mg' is the combined total of fisetin plus quercetin, resveratrol, TMG, and other ingredients - not 2,000 mg of pure fisetin. For a clean, honest dose, favor a product that lists pure fisetin at 98% standardization and tells you exactly how many milligrams of fisetin (not 'blend') you are getting.
Is fisetin safe?
At the doses studied, fisetin appears well tolerated with no serious adverse events reported in short-term work, and it is a compound found naturally in strawberries and apples. But completed long-term human safety data is lacking, and it can interact with blood thinners, chemotherapy, and immunosuppressants. Pregnant and breastfeeding people should avoid it for lack of data. If you take interacting medications, clear it with your clinician first.
Related Reading
Sources
- Yousefzadeh MJ, et al. Fisetin is a senotherapeutic that extends health and lifespan. EBioMedicine. 2018;36:18-28.
- Wissler Gerdes EO, et al. Strategies for late phase preclinical and early clinical trials of senolytics. Mech Ageing Dev. 2021;200:111591.
- Henschke A, et al. Targeting Cellular Senescence with Liposome-Encapsulated Fisetin: Evidence of Senomorphic Effects. Int J Mol Sci. 2025.
- Mayo Clinic. AFFIRM-LITE: A Phase II Double-blind, Placebo-controlled Trial of Fisetin to Alleviate Frailty (ongoing). ClinicalTrials.gov.
Scores and tiers are our independent opinion, formed by applying a published rubric to label data, third-party certifications, and the research record. They are not statements of objective fact about a product and not a lab test. Where we report a brand-specific fact, it comes from a cited source or a public certification; where verification is missing, we say so rather than assume a result.
FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. Dietary supplements are not intended to diagnose, treat, cure, or prevent any disease. Always consult with a qualified healthcare professional before starting any supplement regimen.