Fisetin vs Quercetin: Not Interchangeable in a Formula
Fisetin and quercetin are both flavonols, and they differ by a single hydroxyl group. Quercetin carries five; fisetin lacks the one at position 5 and carries four.[1] That small structural gap sits behind a large commercial one. Quercetin is a commodity ingredient with three decades of human studies, an FDA GRAS notice for a high-purity grade and several absorption-enhanced forms on the market. Fisetin is a purification-intensive ingredient whose reputation rests largely on preclinical work identifying it as a potent senolytic, a compound that selectively clears senescent cells.
For a formulator, the useful question is not which of the two is better but which one the product actually needs, and whether one can stand in for the other. That depends on the job: the matrix and pH the ingredient has to survive, the kind of evidence the label will lean on, the regulatory route to market, and the dosing pattern the product is built around.
The two are not interchangeable. Fisetin is measurably more stable in solution; quercetin is far better supported in humans and in regulation. Neither has been shown to clear senescent cells in people when used on its own.
This fisetin vs quercetin comparison covers structure and supply, stability in solution, absorption, senolytic and clinical evidence, the dosing patterns used in research, safety data and regulatory status, and how to tell them apart in the laboratory, before closing with a decision table for choosing one, the other, or both.
01 Framing
Fisetin vs Quercetin: The Short Answer
Most comparisons of the two are written for consumers and settle on a slogan: fisetin is the stronger senolytic, quercetin has more human research. Both halves are roughly true, and both hide the details that matter to a product team.
The first half depends on the model. Fisetin topped a ten-flavonoid screen on senescent mouse fibroblasts,[2] but on senescent adipose progenitor cells quercetin and dasatinib outperformed it,[3] and in the multi-site lifespan programme run for the US National Institute on Aging, fisetin did not extend life.[4] The second half hides a split. Quercetin's human evidence concerns conventional outcomes such as blood pressure,[5] while its senolytic reputation comes almost entirely from studies in which it was paired with the cancer drug dasatinib.[6][7]
What does separate the two cleanly gets less attention. In a direct comparison, fisetin degraded between two and three and a half times more slowly than quercetin under every pH, temperature and protein condition tested.[1] Quercetin, for its part, holds a position in the US food supply that fisetin lacks,[8] a deeper human safety record,[9] and a supply chain built on an abundant precursor. Those differences decide more formulation questions than the senolytic debate does.
Choose between them on stability, evidence type, regulatory route and dosing pattern. The senolytic headline settles none of these.
02 Identity
Structure and Supply: One Hydroxyl, Two Supply Chains
The table sets the two side by side on the attributes that appear on a specification or drive its cost.
| Attribute | Fisetin | Quercetin |
|---|---|---|
| Chemical name | 3,3′,4′,7-Tetrahydroxyflavone[10] | 3,3′,4′,5,7-Pentahydroxyflavone[11] |
| Formula and molecular weight | C15H10O6, 286.24 | C15H10O7, 302.24 as the anhydrous form |
| CAS number | 528-48-3 | 117-39-5 anhydrous; 6151-25-3 dihydrate |
| Hydroxyl groups | Four | Five[1] |
| Main industrial source | Heartwood of Cotinus coggygria, the smoke tree, and related Rhus species[12][10] | Rutin from Sophora japonica flower buds, hydrolysed to quercetin[13] |
| Route to high purity | Enrichment from a crude extract in which fisetin is a minor flavonoid[12] | Removal of the sugar from an abundant glycoside, then purification[13] |
| Typical dietary intake | 0.4 mg per day in a Japanese intake survey[14] | 8.3 mg per day in the same survey;[14] about 25 mg per day estimated for the US[11] |
| Richest common food source | Strawberries, at about 160 µg/g[14] | Onions, where it occurs mainly as glucosides[15] |
Two rows carry most of the commercial consequence. Quercetin is made by cutting the sugar off rutin, a glycoside that Sophora japonica flower buds contain in abundance, so a high-purity grade is one hydrolysis and a purification away from a cheap and plentiful precursor.[13] Fisetin has no equivalent shortcut. In smoke tree heartwood it makes up about 5% of an ethanolic extract, behind fustin, sulfuretin and butin,[12] so every percentage point above that level is paid for in purification. The price gap between the two ingredients, and the difference in how many producers can supply each at scale, follow directly from that.
The dietary rows matter for regulation as much as for marketing. In the same Japanese survey, people consumed about twenty times more quercetin than fisetin,[14] and the distance between what the diet supplies and what a supplement delivers is correspondingly wider for fisetin, as §06 shows.
The dihydrate trap
Quercetin is widely traded as the dihydrate, CAS 6151-25-3, in which two molecules of water make up about 10.7% of the mass. A powder assayed at 98% on a dihydrate basis therefore holds about 87.6% anhydrous quercetin. Before comparing prices per kilogram, or moving a formula from one supplier to another, check which basis each certificate of analysis uses.
03 Stability
Stability in Solution: Fisetin's Clearest Advantage
The only direct comparison we found measured both compounds under identical conditions. It followed high-purity material at about 30 µmol/L in phosphate buffer by absorbance, at 360 nm for fisetin and 368 nm for quercetin.[1] The table converts the published first-order rate constants into half-lives, calculated as ln 2 divided by the rate constant.
| Condition in solution | Fisetin rate constant, per hour | Fisetin half-life | Quercetin rate constant, per hour | Quercetin half-life |
|---|---|---|---|---|
| pH 6.0, 37 °C | 0.0083 | About 84 hours | 0.0281 | About 25 hours |
| pH 6.8, 37 °C | 0.0358 | About 19 hours | 0.0799 | About 8.7 hours |
| pH 7.5, 37 °C | 0.202 | About 3.4 hours | 0.375 | About 1.8 hours |
| pH 6.8, 50 °C | 0.124 | About 5.6 hours | 0.245 | About 2.8 hours |
| pH 6.8, 65 °C | 0.490 | About 1.4 hours | 1.42 | About 29 minutes |
| pH 6.8, 37 °C, 0.20 g/L casein | 0.0176 | About 39 hours | 0.0380 | About 18 hours |
| pH 6.8, 37 °C, 0.10 g/L whey protein isolate | 0.0298 | About 23 hours | 0.0597 | About 12 hours |
Across all seven conditions, fisetin's half-life was between 1.9 and 3.4 times quercetin's. The authors attribute the difference to hydroxylation: more hydroxyl groups make a flavonoid less stable, and quercetin carries one more than fisetin.[1]
Two details are easy to miss. First, fisetin was the more pH-sensitive of the two in relative terms. Moving from pH 6.0 to 7.5 raised its rate constant about 24-fold, against about 13-fold for quercetin, so fisetin's advantage is largest in acidic systems and narrows towards neutral pH, although it never disappears. Second, both compounds degraded fastest in the conditions many products involve: near-neutral pH, warm processing and long hold times. Protein slowed the loss of both, with casein and soy protein stabilising more than whey protein through hydrophobic binding.[1]
These are dilute-solution laboratory figures and are best read as a ranking rather than a shelf-life prediction. For a ready-to-drink beverage, a functional shot or an aqueous serum, the ranking favours fisetin. It does not make either compound stable in a neutral liquid.
04 Absorption
Solubility and Absorption: No Shortcut for Either
On solubility, the two are closer than marketing suggests. Fisetin's aqueous solubility has been measured at about 10.45 µg/mL,[16] and quercetin is likewise poorly soluble, which is the main property limiting its oral absorption.[17] Neither dissolves in a water-based drink at a meaningful dose, so solubility is not a reason to prefer one over the other.
Where they differ is in how much is known and what can be done about it. Quercetin has been studied in human volunteers for three decades. In a mass-balance study in people with an ileostomy, absorption was 52% from the quercetin glucosides in onions, 24% from pure quercetin aglycone and 17% from rutin,[15] which is why glucoside forms of quercetin are sold as ingredients in their own right. What reaches the blood circulates mainly as conjugates, with very little free quercetin.[9] A lecithin-based formulation raised plasma quercetin up to about twentyfold over the unformulated powder in a crossover study run by the formulation's developer.[17]
Fisetin's human pharmacokinetics rest on a single study. After a 1,000 mg dose of plain fisetin, free fisetin was quantifiable in plasma for only two hours and was exceeded by its methylated metabolite geraldol. A formulation embedding fisetin micelles in a fenugreek galactomannan hydrogel produced 26.9 times the exposure. Fifteen volunteers took part, the plain material was 98.2% fisetin extracted from Rhus succedanea, and the study was funded by the formulation's developer.[10]
The two formulation studies cannot be compared with each other, since the analytical methods, doses and reference materials all differ. What the comparison does show is depth. A quercetin formulator can choose between aglycone, glucosides and several enhanced forms with published human data behind them; a fisetin formulator starts from one study.
Neither molecule is absorbed well enough as a plain powder for solubility to decide the choice. The depth of formulation data does.
05 Evidence
Senolytic and Clinical Evidence, Level by Level
Most of the attention on both compounds comes from senolytic research. The table separates the evidence by level, because the ranking between them changes as the model moves from cells to mice to people.
| Level | Fisetin | Quercetin |
|---|---|---|
| Cells | Most potent of ten flavonoids screened on senescent mouse fibroblasts; quercetin was ineffective at the 5 µM dose used in the screen[2] | Selectively reduced senescent human endothelial cells but was less effective on senescent preadipocytes; dasatinib showed the opposite pattern, and the combination covered both[6] |
| Cell-type dependence | Not a universal senolytic: activity depends on the cell type and on how senescence was induced[3] | On senescent mouse adipose progenitor cells, quercetin or dasatinib, alone or together, were more effective than fisetin[3] |
| Mouse lifespan | Extended median and maximum lifespan when fed late in life in one study;[2] in the NIA Interventions Testing Program, did not extend lifespan in either sex and did not lower p16Ink4a in liver, kidney or brain at the doses used[4] | Evidence in mice comes from dasatinib plus quercetin, which reduced senescent-cell burden and delayed age-related decline in the original work[6] |
| Humans, senescence | By late 2025, 32 fisetin studies were registered on ClinicalTrials.gov; the early human signals of biological effect reviewed at that point came from dasatinib plus quercetin, not fisetin[18] | Only in combination: in a 60-woman phase 2 trial, dasatinib plus quercetin did not change the primary bone-resorption endpoint, and the skeletal response was driven mainly by women with a high senescent-cell burden[7] |
| Humans, other outcomes | Phase I/II knee osteoarthritis trial, 74 participants: no significant benefit for pain, function or cartilage, and no significant safety concerns[19] | Meta-analysis of seven randomised trials with 587 participants: small reductions in blood pressure, significant in trials using 500 mg per day or more and not below[5] |
Read level by level, the popular ranking falls apart. Fisetin is the stronger single agent in some cell models and not in others, and its best mouse result was not reproduced in the Interventions Testing Program, a study whose author list included members of the team behind the original fisetin work.[4] Quercetin's senolytic credentials are borrowed from a combination with a prescription oncology drug, and even that combination missed its primary endpoint in the first randomised trial in healthy older women.[7]
The senior author of that trial drew the practical conclusion himself. In the accompanying Mayo Clinic release, he said the findings argue against using commercial quercetin, or related compounds such as fisetin, as anti-ageing agents without knowing whether the user has a high enough senescent-cell burden to benefit, or what dose and schedule would be effective and safe.[20]
For quercetin, the conventional human evidence is real but modest. For fisetin, human evidence is at an early stage and, where an outcome has been tested, negative so far. A finished product that leans on senolytic language for either ingredient is describing a research direction, not a demonstrated effect in people.
06 Dosing
Daily Intake or Intermittent Pulse: How Research Doses Each
The two compounds are studied on different schedules, and the schedule shapes a product more than the molecule does.
| Study | Compound and dose | Schedule |
|---|---|---|
| Blood pressure meta-analysis[5] | Quercetin, with effects seen at 500 mg per day or more | Daily |
| Postmenopausal bone trial[7][20] | Dasatinib 100 mg plus quercetin 1,000 mg | Three consecutive days every 28 days, five cycles over 20 weeks |
| Knee osteoarthritis trial[19] | Fisetin, 20 mg per kg of body weight per day | Two consecutive days followed by 28 days off, three cycles |
| AFFIRM-LITE, Mayo Clinic[16] | Fisetin, up to 20 mg per kg of body weight | Short oral course |
| First human pharmacokinetic study[10] | Fisetin, 1,000 mg | Single dose |
The intermittent schedules follow from how senolytics are thought to work. In the original fisetin study, acute or intermittent dosing reduced senescence markers in mice, consistent with a hit-and-run mechanism in which the compound needs to act only briefly.[2] A 70 kg adult on the osteoarthritis protocol takes 1,400 mg of fisetin on each dosing day and 2,800 mg per course, or roughly 1.43 g of a 98% powder per day.
Set against diet, the two sets of numbers diverge sharply. That 1,400 mg is about 3,500 times the 0.4 mg of fisetin consumed daily in the Japanese intake survey,[14] while the 1,000 mg of quercetin used in the bone trial is about 40 times the estimated US dietary intake of 25 mg.[11] The further a dose sits from dietary exposure, the more weight falls on dedicated safety data, which is the subject of §07.
For product design, the choice of compound usually implies a format. Quercetin fits a daily capsule, tablet or drink mix. A fisetin product modelled on the trial protocols is an intermittent pack of a few high-dose days per month, which changes capsule count, label directions and the claims that can be supported. The trial regimens were given under medical supervision in research settings and are not serving recommendations.
07 Safety and regulation
Safety Data and Regulatory Status: Quercetin Is Further Along
What the safety data cover
Quercetin has been examined far more thoroughly, and that includes findings a supplier would rather not mention. A review by Germany's Federal Institute for Risk Assessment found that adverse effects in human intervention studies were rare and mild, but that adequate data on long-term use, meaning more than 12 weeks at 1,000 mg or more per day, were not available. From animal work it identified possible concerns, including enhancement of kidney toxicity where the kidney is already damaged and promotion of tumours in oestrogen-dependent cancer, and it considered drug interactions.[9] In a two-year feed study by the US National Toxicology Program, quercetin produced some evidence of carcinogenic activity in male rats, based on renal tubule adenomas, and no evidence in females, at intakes of about 40 to 1,900 mg/kg per day.[11]
Fisetin's record is shorter rather than cleaner. The single human pharmacokinetic study reported no significant adverse events after 1,000 mg, with one report each of bloating and reduced appetite, and summarised animal data showing no toxicity after single oral doses of up to 2,000 mg/kg in mice or over 90 days of dietary feeding, and no mutagenicity in the Ames test.[10] The knee osteoarthritis trial reported no significant safety concerns.[19] We found no two-year carcinogenicity study of fisetin comparable to the National Toxicology Program work on quercetin. The absence of adverse findings for fisetin reflects how little it has been tested, not a demonstrated safety advantage.
Regulatory position
| Question | Fisetin | Quercetin |
|---|---|---|
| US conventional foods | We found no FDA GRAS notice. Any GRAS position would rest on a self-affirmed determination rather than an FDA notification | GRAS notice GRN 341 for a high-purity quercetin, which received FDA's response in November 2010[8] |
| US dietary supplements | Sold as a dietary ingredient; the identity of each lot must be verified under 21 CFR Part 111 | The same framework applies |
| EU health claims | No claims assessed | EFSA assessed antioxidant, cardiovascular, mental performance and liver and kidney claims in 2011;[21] none has been authorised |
| EU Novel Food | Status to be confirmed with the Commission's catalogue and the national authority; dietary exposure is very low (§06) | Status of isolated high-dose forms also to be confirmed; dietary exposure is well established |
For label and claims teams
Quercetin's regulatory advantages attach to specific materials and uses: GRN 341 covers the notifier's high-purity quercetin under its stated conditions of use, not every quercetin on the market. Fisetin's position depends even more heavily on the individual supplier's documentation. In both cases the finished-product owner carries responsibility for status and claims in each market.
08 Testing
Telling Them Apart: UV Cannot, HPLC Can
In buffer, fisetin's main absorption band peaks at 360 nm and quercetin's at 368 nm.[1] Eight nanometres apart, on broad and overlapping bands, the two cannot be distinguished by a UV reading, and a total-flavonoid assay counts both as one number. Only a chromatographic method that resolves the two peaks, calibrated against a reference standard for each, can say how much of a powder is which.
This is not a theoretical concern for fisetin buyers. Quercetin occurs naturally in smoke tree heartwood alongside fisetin,[22] so it can appear as a related substance in fisetin grades, particularly the lower ones. And when two yellow flavonol powders differ substantially in production cost, a specification that accepts a UV or total-flavonoid figure leaves room for dilution with the cheaper one. How the assay basis and the chromatogram fit into a fisetin specification is covered on our fisetin powder grades and specification page.
Combination products need the same discipline in the other direction. A formula carrying both compounds should specify a method that separates them and reports each on its own basis, with quercetin's dihydrate or anhydrous basis stated (§02), rather than a combined flavonol figure.
09 Choosing
Fisetin or Quercetin? A Decision Table for Product Teams
| If the product needs | Lean towards | Because |
|---|---|---|
| Human outcome data behind a daily supplement | Quercetin | Randomised trials and meta-analyses exist for quercetin; fisetin's only outcome trial so far was negative[5][19] |
| A route into US conventional food or beverages | Quercetin | GRN 341 covers a high-purity grade; we found no notified GRAS for fisetin[8] |
| Survival in a liquid, a warm process or near-neutral pH | Fisetin | Half-life 1.9 to 3.4 times quercetin's under identical conditions, although neither is stable at neutral pH[1] |
| An intermittent, research-style format for healthy-ageing positioning | Fisetin | The published pulse protocols use fisetin alone; human benefit remains unproven[19][18] |
| Delivery-system development with human precedent | Quercetin, or fisetin at the 98% grade | Quercetin has several enhanced forms with human data; fisetin has one human formulation study[17][10] |
| The lowest cost per gram of active | Quercetin | An abundant glycoside precursor against a heavily purified heartwood compound[13][12] |
Using both
Fisetin and quercetin are often sold together, and the reasoning usually offered is that two related flavonols cover more ground than one. No published human trial has tested that combination against either compound alone. The dasatinib plus quercetin data cannot be carried over, because dasatinib is not a flavonoid and was paired with quercetin precisely because the two act on different senescent cell types.[6] A combination can still be a reasonable design choice, but it should not claim synergy, it needs each compound assayed separately (§08), and it has to reconcile two dosing logics: a daily quercetin pattern and an intermittent fisetin pattern do not sit comfortably in one capsule.
PhytoVale supplies fisetin rather than quercetin, which is one reason this guide has tried to give quercetin its due. Our fisetin is extracted from the trunk and thick-branch wood of Cotinus coggygria and offered at 10%, 50%, 85% and 98% by HPLC, with grades and specification details on the fisetin powder product page. Samples are free, MOQ is 1 kg, and quotations are returned within 24 hours.
10 Questions
Fisetin vs Quercetin: Frequently Asked Questions
Is fisetin better than quercetin?
Not across the board. Fisetin is more stable in solution and was the stronger single agent in some senolytic cell models. Quercetin has far more human outcome data, an FDA GRAS notice for a high-purity grade and more formulation options. The better choice depends on the product's matrix, the evidence it will rely on, its market and its dosing pattern.
Can fisetin and quercetin be taken together?
They can be formulated together, and many products do so. What is missing is evidence that the pair does more than either compound alone, because no human trial has tested it. The senolytic trials that used quercetin paired it with dasatinib, not fisetin, and the fisetin trials used fisetin on its own. A combination product should present each ingredient on its own evidence and avoid synergy claims.
Can I replace quercetin with fisetin milligram for milligram?
On a molar basis the numbers are close but not equal. Fisetin is the lighter molecule, so 500 mg of anhydrous quercetin corresponds to about 474 mg of fisetin, and 500 mg of quercetin dihydrate to about 423 mg. Molar equivalence does not make the ingredients equivalent, though. Their stability, absorption data and evidence base differ, and a claim substantiated with quercetin studies cannot be transferred to a fisetin product.
Which foods contain the most fisetin and quercetin?
In the Japanese intake survey, strawberries were the richest fisetin source at about 160 µg/g, followed by apples at 26.9 µg/g and persimmons at 10.5 µg/g.[14] At that concentration, 100 mg of fisetin corresponds to about 625 g of strawberries. Quercetin is far more widespread: onions supply it mainly as glucosides, and tea supplies it mainly as rutin.[15]
Why does fisetin cost so much more than quercetin?
Because of where each comes from. Quercetin is released from rutin, an abundant glycoside, in essentially one chemical step. Fisetin is a minor flavonoid in smoke tree heartwood and has to be separated from related compounds present at higher levels. The yield arithmetic behind that difference is set out in the FAQ on our fisetin powder page.
Is quercetin dihydrate the same as quercetin?
It is the same molecule in a crystalline form that holds two molecules of water, registered under its own CAS number, 6151-25-3. About 10.7% of its mass is water, so a gram of the dihydrate delivers less quercetin than a gram of the anhydrous form. That matters for dose calculations, label declarations and price comparisons, and a certificate of analysis should state which form and which basis it reports.
11 Evidence base
References
[1] Wang, J., Zhao, X.-H. (2016). Degradation kinetics of fisetin and quercetin in solutions affected by medium pH, temperature and co-existing proteins. Journal of the Serbian Chemical Society, 81(3), 243–253. DOI: 10.2298/JSC150706092W
[2] Yousefzadeh, M. J., Zhu, Y., McGowan, S. J., Angelini, L., Fuhrmann-Stroissnigg, H., Xu, M., et al. (2018). Fisetin is a senotherapeutic that extends health and lifespan. EBioMedicine, 36, 18–28. DOI: 10.1016/j.ebiom.2018.09.015
[3] Tavenier, J., Nehlin, J. O., Houlind, M. B., Rasmussen, L. J., Tchkonia, T., Kirkland, J. L., Andersen, O., Rasmussen, L. J. H. (2024). Fisetin as a senotherapeutic agent: evidence and perspectives for age-related diseases. Mechanisms of Ageing and Development, 222, 111995. DOI: 10.1016/j.mad.2024.111995
[4] Harrison, D. E., Strong, R., Reifsnyder, P., et al. (2024). Astaxanthin and meclizine extend lifespan in UM-HET3 male mice; fisetin, SG1002 (hydrogen sulfide donor), dimethyl fumarate, mycophenolic acid, and 4-phenylbutyrate do not significantly affect lifespan in either sex at the doses and schedules used. GeroScience, 46(1), 795–816. DOI: 10.1007/s11357-023-01011-0
[5] Serban, M. C., Sahebkar, A., Zanchetti, A., et al. (2016). Effects of quercetin on blood pressure: a systematic review and meta-analysis of randomized controlled trials. Journal of the American Heart Association, 5(7), e002713. DOI: 10.1161/JAHA.115.002713
[6] Zhu, Y., Tchkonia, T., Pirtskhalava, T., et al. (2015). The Achilles’ heel of senescent cells: from transcriptome to senolytic drugs. Aging Cell, 14(4), 644–658. DOI: 10.1111/acel.12344
[7] Farr, J. N., Atkinson, E. J., Achenbach, S. J., et al. (2024). Effects of intermittent senolytic therapy on bone metabolism in postmenopausal women: a phase 2 randomized controlled trial. Nature Medicine, 30(9), 2605–2612. DOI: 10.1038/s41591-024-03096-2
[8] US Food and Drug Administration. GRAS Notice No. GRN 341, high-purity quercetin (Quercegen Pharmaceuticals), response dated November 2010. GRAS Notice Inventory. View source
[9] Andres, S., Pevny, S., Ziegenhagen, R., Bakhiya, N., Schäfer, B., Hirsch-Ernst, K. I., Lampen, A. (2018). Safety aspects of the use of quercetin as a dietary supplement. Molecular Nutrition & Food Research, 62(1), 1700447. DOI: 10.1002/mnfr.201700447
[10] Krishnakumar, I. M., Jaja-Chimedza, A., Joseph, A., Balakrishnan, A., Maliakel, B., Swick, A. (2022). Enhanced bioavailability and pharmacokinetics of a novel hybrid-hydrogel formulation of fisetin orally administered in healthy individuals: a randomised double-blinded comparative crossover study. Journal of Nutritional Science, 11, e74. DOI: 10.1017/jns.2022.72
[11] National Toxicology Program (1992). Toxicology and Carcinogenesis Studies of Quercetin (CAS No. 117-39-5) in F344/N Rats (Feed Studies). NTP Technical Report 409. View source
[12] Pašić, I., Novaković, M., Tešević, V., Milosavljević, S., Petrović, N., Stanojković, T., Matić, I. Z. (2025). Exploring the anticancer potential of extracts and compounds from the heartwood of Cotinus coggygria Scop. wild growing in Serbia. BMC Complementary Medicine and Therapies, 25, 36. DOI: 10.1186/s12906-025-04768-3
[13] Vu, et al. (2023). Separation of mixtures of rutin and quercetin: evaluating the productivity of preparative chromatography. Chemie Ingenieur Technik. DOI: 10.1002/cite.202300050
[14] Kimira, M., Arai, Y., Shimoi, K., Watanabe, S. (1998). Japanese intake of flavonoids and isoflavonoids from foods. Journal of Epidemiology, 8(3), 168–175. DOI: 10.2188/jea.8.168
[15] Hollman, P. C., de Vries, J. H., van Leeuwen, S. D., Mengelers, M. J., Katan, M. B. (1995). Absorption of dietary quercetin glycosides and quercetin in healthy ileostomy volunteers. American Journal of Clinical Nutrition, 62(6), 1276–1282. DOI: 10.1093/ajcn/62.6.1276
[16] Grynkiewicz, G., Demchuk, O. M. (2019). New perspectives for fisetin. Frontiers in Chemistry, 7, 697. DOI: 10.3389/fchem.2019.00697
[17] Riva, A., Ronchi, M., Petrangolini, G., Bosisio, S., Allegrini, P. (2019). Improved oral absorption of quercetin from Quercetin Phytosome®, a new delivery system based on food grade lecithin. European Journal of Drug Metabolism and Pharmacokinetics, 44(2), 169–177. DOI: 10.1007/s13318-018-0517-3
[18] Khosla, S. (2025). Translating senolytics from mice to humans. Innovation in Aging, Gerontological Society of America Annual Scientific Meeting abstract. DOI: 10.1093/geroni/igaf122.679
[19] Tashman, S., et al. (2025). Results from a randomized clinical trial evaluating the senolytic fisetin for treating knee osteoarthritis. Osteoarthritis and Cartilage, 33(Suppl S), abstracts from the 2025 OARSI World Congress on Osteoarthritis. View source
[20] Mayo Clinic (2024). Drugs that kill ‘zombie’ cells may benefit some older women, but not all. News release, 2 July 2024, via ScienceDaily. View source
[21] EFSA Panel on Dietetic Products, Nutrition and Allergies (2011). Scientific Opinion on the substantiation of health claims related to quercetin and protection of DNA, proteins and lipids from oxidative damage (ID 1647), “cardiovascular system” (ID 1844), “mental state and performance” (ID 1845), and “liver, kidneys” (ID 1846) pursuant to Article 13(1) of Regulation (EC) No 1924/2006. EFSA Journal, 9(4), 2067. DOI: 10.2903/j.efsa.2011.2067
[22] Valianou, L., Stathopoulou, K., Karapanagiotis, I., Magiatis, P., Pavlidou, E., Skaltsounis, A. L., Chryssoulakis, Y. (2009). Phytochemical analysis of young fustic (Cotinus coggygria heartwood) and identification of isolated colourants in historical textiles. Analytical and Bioanalytical Chemistry, 394, 871–882. DOI: 10.1007/s00216-009-2767-z
Reviewed by
Prof. Bingji MaScientific Advisor at PhytoVale. Professor and medicinal plant science expert. Research focus covers Chinese medicinal materials, phytochemistry, natural products and medicinal plant quality.
Written by
FloraContent Editor at PhytoVale. Product content and editorial specialist, focused on botanical ingredient specifications, sourcing information and B2B technical content.
This article is intended for ingredient sourcing, formulation and technical information only. It summarises published research on fisetin and quercetin and is not medical advice or a claim for any PhytoVale product. Several figures come from single laboratory or clinical studies of specific materials, and the half-lives and conversions shown were calculated by PhytoVale from published data. Nothing here should be treated as a commercial specification or a recommended dose. Identity, assay and stability must be verified on the actual lot, and finished-product manufacturers remain responsible for regulatory status, permitted claims and labelling in their target markets.
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