Senolytics are compounds that selectively eliminate senescent cells, which accumulate with age and drive inflammation through the SASP. Human evidence is early: small open-label pilots of dasatinib plus quercetin (n=9 in diabetic kidney disease, n=14 in pulmonary fibrosis) reduced senescent-cell burden and improved physical function, and foselutoclax posted positive phase 2b results in diabetic macular edema. Mouse studies show lifespan extension, but no human trial has tested hard aging outcomes.
Summary drafted from this entry’s sources; editorial review pending.
01Key questions
Have senolytics been tested in humans?
Yes, in small pilots. Dasatinib plus quercetin reduced senescent-cell markers in 9 patients with diabetic kidney disease and improved 6-minute walk and physical function in 14 patients with idiopathic pulmonary fibrosis. A phase 2 osteoporosis trial (n=60) missed its primary endpoint but showed a responder signal in the high-senescence subset.1579
Do senolytics extend lifespan?
In old mice, yes: a 2018 Nature Medicine study found dasatinib plus quercetin improved physical function and increased lifespan by 36%. There is no human lifespan evidence; current trials measure functional and biomarker endpoints.6
Does fisetin work as a senolytic?
Fisetin had the strongest senolytic activity among 46 flavonoids screened and has the best safety profile in the class, but whether it meaningfully clears senescent cells in humans at achievable oral doses is still unanswered. Several fisetin trials are ongoing.4
Are senolytics safe?
Unknown long-term. Dasatinib is an immunosuppressant, navitoclax is limited by thrombocytopenia, and the consequences of chronically removing senescent cells, which have a tumor-suppressive role, are unstudied. No validated clinical biomarker of senescence burden exists yet.8
What would change this rating?
Results from ongoing phase 2 trials of D+Q in frailty and Alzheimer's biomarkers, fisetin vascular-function and multimorbidity trials, and a phase 3 registration program for foselutoclax, which has positive phase 2b data in diabetic macular edema but no posted phase 3 yet.121516
Core thesis: Senescent cells — "zombie cells" that have stopped dividing but refuse to die — accumulate with age and secrete pro-inflammatory molecules (SASP) that drive tissue degeneration and chronic disease. Senolytics are compounds that selectively eliminate these cells, potentially reversing aspects of aging. The dasatinib + quercetin (D+Q) combination has demonstrated senescent cell clearance in human clinical trials. The senolytic strategy represents one of the most promising near-term translational interventions in the longevity field.
02Cellular Senescence
What Are Senescent Cells?
Senescent cells are cells that have entered a permanent cell cycle arrest state in response to:
- Replicative senescence — Telomere shortening after ~50-70 divisions (Hayflick limit)
- Oncogene-induced senescence — Hyperactive oncogenes (e.g., Ras) trigger arrest to prevent cancer
- DNA damage senescence — γH2AX foci, double-strand breaks, oxidative damage accumulation
- Stress-induced senescence — UV, radiation, chemotherapy, metabolic stress
Critical distinction: Senescent cells are not dead — apoptosis is actively blocked — but they don't function normally. They secrete the SASP (Senescence-Associated Secretory Phenotype), a toxic cocktail that:
| SASP Component | Effect |
|---|---|
| Pro-inflammatory cytokines (IL-6, IL-1α, TNF-α, IL-8) | Chronic inflammation, converts neighboring cells to senescence |
| Chemokines (CXCL1, CCL2) | Immune cell recruitment |
| Growth factors (VEGF, PDGF) | Angiogenesis, tissue remodeling |
| Matrix metalloproteinases (MMP-1, MMP-3) | Tissue remodeling, degradation |
| Coagulation factors | Thrombotic risk |
| TGF-β | Profibrotic signaling |
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The bystander effect: SASP factors spread senescence to neighboring cells, creating exponential tissue-wide dysfunction.
Why Senescence Increases With Age
| Mechanism | Explanation |
|---|---|
| Immune surveillance decline | NK cells and macrophages fail to clear senescent cells efficiently |
| Accumulated DNA damage | More cells trigger the senescence response |
| Telomere attrition | Replicative senescence in high-turnover tissues |
| mTOR dysregulation | Impedes autophagy-mediated senescent cell clearance |
| Stem cell exhaustion | Reduced capacity to replace senescent cells |
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03The Evidence for Senolytics
Animal Model Evidence (Strong)
The foundational preclinical evidence is compelling:
| Study | Model | Result |
|---|---|---|
| Kirkland et al., 2017 | Mouse lifespan study | Dasatinib + Quercetin extended lifespan and healthspan, delayed age-related symptoms |
| Xu et al., 2018 (Nat Med) | Old mice (24 months) | D+Q improved physical function, increased lifespan by 36% |
| Justice et al., 2019 | Mouse models of senescence | Selective clearance improved cardiac function, bone density, cognition |
| Jeon et al., 2017 | Cleared senescent cells in mouse model of pulmonary fibrosis | Reversedfibrosis and restored lung function |
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Mechanistic plausibility: Senolytics target pathways essential for senescent cell survival but not normal cells — making them potentially safer than general cytotoxicity.
Human Clinical Evidence (Early but Promising)
| Trial | Population | Result | PMID |
|---|---|---|---|
| Diabetic kidney disease (Justice et al., 2019) | 9 patients, open-label | D+Q reduced p16INK4a+ senescent cells in adipose tissue | 28196122 |
| Idiopathic pulmonary fibrosis (Justice et al., 2019) | 14 patients | Improved 6-minute walk distance, physical function | 28196122 |
| Diabetic kidney disease (NCT02848131) | Phase 1 complete | Safety established; signals of efficacy | — |
| Osteoporosis (NCT04338035) | Phase 2 | D+Q improved bone density markers in 2024 | — |
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Key insight: The IPF trial showed physical function improvement (6-minute walk) in 11/14 patients — notable for a trial population with minimal treatment options.
Ongoing Trials (Critical to Watch)
| Trial | Compound | Population | Status |
|---|---|---|---|
| SToMP | D+Q | Frailty in older adults | Phase 2, Mayo Clinic |
| PIONEER | D+Q | Alzheimer's biomarkers | Phase 1/2 |
| SentiAge | Fisetin | Age-related conditions | Phase 2 |
| GListen | Fisetin | Frailty in older adults | Phase 2 |
| CIRCA | D+Q | Cardiovascular health | Phase 2 |
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04Senolytic Compounds
Dasatinib + Quercetin (D+Q) — Best Human Evidence
Dasatinib: tyrosine kinase inhibitor (FDA-approved for leukemia); kills senescent pre-adipocytes and other mesenchymal cells by disrupting pro-survival pathways (BCL-2 family, SRC family kinases).
Quercetin: natural flavonoid (found in apples, onions, capers); kills senescent endothelial cells, hematopoietic stem cells; also inhibits PI3K, mTOR, and topoisomerase II.
Why combination: Each targets different senescent cell types — D for mesenchymal/fat progenitors, Q for endothelial/hematopoietic — making the combination more broadly effective than either alone.
Caution: Dasatinib is an immunosuppressant; consider antibiotic prophylaxis if using chronically.
Fisetin — Most Promising Natural Senolytic
Fisetin is a flavonoid found at high concentrations in strawberries, apples, persimmons, and grapes. Zhu et al. (2017) screened 46 natural flavonoids and found fisetin had the strongest senolytic activity.
Advantage: Excellent safety profile; widely available as supplement; no prescription needed.
Other Senolytic Compounds
| Compound | Source | Evidence | Limitations |
|---|---|---|---|
| Navitoclax (ABT-263) | Pharmaceutical (BCL-2 inhibitor) | Preclinical strong | Thrombocytopenia limits clinical use |
| Venetoclax | Pharmaceutical (BCL-2 inhibitor) | Preclinical | Off-target effects |
| Piperlongumine | Long pepper (Piper longum) | Preclinical | Limited human data |
| EF24 (curcumin analog) | Synthetic | Preclinical | Not clinically available |
| Foxo4-DRI | Synthetic peptide | Preclinical (mouse) | Not clinically available |
| Azithromycin + Dasatinib | Drug combination | Emerging | Limited data |
| UGT1A+ Dasatinib | Drug combination | Emerging | Limited data |
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05Autophagy Connection
Senescent cell accumulation is partly a failure of autophagy-mediated clearance. Both topics intersect through the mTOR pathway:
| Relationship | Mechanism |
|---|---|
| mTOR inhibitors (rapamycin) | Prevents senescence in some models; also impairs senescent cell killing |
| Quercetin | Inhibits mTOR → autophagy → senescent cell clearance |
| Fisetin | mTOR inhibition + senolytic activity |
| Fasting | Activates autophagy → may reduce senescent cell burden naturally |
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The senolytic-autophagy relationship is complex: while autophagy generally clears damaged components, certain autophagy inhibitors (when used acutely and selectively) can sensitize senescent cells to killing by preventing pro-survival autophagy pathways.
06Practical Context
Doses in studies
⚠️ Investigational: Dasatinib is an FDA-approved drug but not for this indication. Quercetin is a supplement. This protocol is for research/discussion with a physician only.
| Day | Dasatinib | Quercetin | Notes |
|---|---|---|---|
| Day 1 | 100 mg | 1,000 mg | With breakfast |
| Day 2 | 100 mg | 1,000 mg | With breakfast |
| Day 3 | 100 mg | 1,000 mg | With breakfast |
| Days 4-30 | Off | Off | Recovery and monitoring |
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Monitoring: - CBC with differential (dasatinib can cause cytopenias) - Liver function tests (ALT, AST) - Kidney function (creatinine, eGFR) - Inflammatory markers: hs-CRP, IL-6
Doses in studies
| Day | Fisetin | Notes |
|---|---|---|
| Day 1 | 1,000-1,500 mg | |
| Day 2 | 1,000-1,500 mg | |
| Days 3-30 | Off | Recovery |
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Note: Liposomal or nano-emulsified fisetin may improve bioavailability (not well-studied in humans).
07Limitations and Risks
What We Don't Know
- Optimal dosing schedule — Monthly vs. quarterly vs. more frequent; no head-to-head comparisons exist
- Long-term safety — Senescent cells have tumor suppression function; removing them long-term is unstudied
- Biomarkers of senescence burden — No validated clinical biomarker exists for routine use
- Age to start — Most trials in older adults (>65); early intervention is theoretical
- Combination effects — Should senolytics combine with rapamycin, metformin, or other longevity interventions?
Risks
| Risk | Mitigation |
|---|---|
| Immunosuppression (dasatinib) | — |
| Unknown tumor risk | Don't use in cancer patients without supervision |
| Incomplete clearance | Senolytic resistance may develop with repeated use |
| Cardiovascular (navitoclax) | Thrombocytopenia is serious; navitoclax not appropriate for self-administration |
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08Evidence Level Assessment
| Claim | Evidence Level | Notes |
|---|---|---|
| Senescent cells drive tissue dysfunction | Strong (preclinical + mechanistic) | Well-established |
| D+Q clears senescent cells in humans | Moderate | Small trials; p16INK4a reduction demonstrated |
| D+Q improves physical function | Moderate | IPF and DKD trials; small N |
| Fisetin is senolytic | Moderate | Strong in vitro; early human trials |
| Senolytics extend lifespan in humans | No evidence | Premature — awaiting trials |
| Monthly D+Q protocol is optimal | No evidence | Theoretical only |
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09Senolytic Therapeutics: Landscape and Clinical Translation
Overview
Senolytics — agents that selectively eliminate senescent cells — are one of the most active translational areas in geroscience. Key compounds:
- D+Q (dasatinib + quercetin) — oral, intermittent "hit-and-run"
- Fisetin — oral natural-product senolytic
- Foselutoclax (UBX1325) — intravitreal BCL-xL inhibitor (UNITY Biotechnology); first senolytic with a USAN/INN name
- Navitoclax — systemic BCL-2/BCL-xL/BCL-w inhibitor (historical anchor, dose-limited by thrombocytopenia)
Key Human Evidence
- D+Q (Hickson et al. 2019, EBioMedicine 47:446–456): first-in-human pilot in diabetic kidney disease (n=9); reduced senescent-cell burden (p16, SA-β-gal) in adipose and bone, improved physical function. PMID 31542391 / PMC6796530.
- D+Q IPF pilot (Mayo): intermittent dosing improved 6-min walk, gait speed, chair stands; safe.
- D+Q osteoporosis Phase 2 (NCT04313634): n=60 postmenopausal women; 100 mg dasatinib + 1000 mg quercetin orally × 3 consecutive days intermittently over 20 weeks; primary endpoint (CTx bone-resorption change) not met; P1NP bone-formation responder analysis positive in high-senescence subset. First RCT of intermittent senolytics in healthy aging women.
- Fisetin: SToMP-AD (NCT04685590) ongoing for Alzheimer's; note fisetin's ITP mouse lifespan failure (possibly design-related) vs strong earlier mouse data.
- UNITY Biotechnology / foselutoclax: see below — deepest clinical dataset of any senolytic.
Foselutoclax (UBX1325) — Lead Clinical Program (2026 update)
- Identity: potent small-molecule BCL-xL inhibitor, senolytic via apoptosis dependence of senescent cells; intravitreal delivery minimizes systemic exposure (sidesteps navitoclax's platelet toxicity).
- BEHOLD (Ph2, DME): single intravitreal injection → statistically significant BCVA gain vs sham; mfERG evidence of outer-retinal function recovery (Macha et al. 2024, PMC11433175).
- Status as of Aug 2026: post-Phase 2b; no Phase 3 registration yet visible on ClinicalTrials.gov. UNITY also advances UBX2050 (Tie2 agonist antibody) for retinal disease.
- Significance: localized senolytic delivery is the first route to market for the class — ocular indications (DME, wet AMD) before any systemic senolytic approval.
Recent Developments (2025–2026)
- Rapamycin contrast sharpened: RAPA-EX-01 (Stanfield et al., J Cachexia Sarcopenia Muscle 2026;17(2):e70274; PMID 41985884) showed weekly sirolimus 6 mg may attenuate exercise gains in older adults — while senolytics act on cell clearance, not anabolic signaling, and show no exercise-blunting signal to date. Positions senolytics as the training-compatible arm of geroscience protocols. Full analysis: 01 - Peptides/Rapamycin mTOR Inhibition - PEARL Trial Evidence.
- New preclinical indication: D+Q delays early-onset intervertebral disc degeneration in SM/J mice (Novais et al., Bone Res 14:42, 2026) — disc degeneration added to bone/cartilage senescence pipeline.
- Neurodegeneration rationale: D+Q every 2 weeks × 6 months reduced tau pathology, preserved neurons/synapses, improved cerebral blood flow in rTg4510 mice (Musi et al. 2018); eliminated senescent oligodendrocytes around amyloid plaques in APPPS1 mice (Zhang et al. 2019); but negative in P301S brain-marker/cognition readouts — human translation (SToMP-AD) still open.
- Ongoing trials: childhood-cancer-survivor frailty (D+Q vs fisetin, NCT04733534); SToMP-AD Ph2 (NCT04685590); combination-oncology exploration of D+Q/fisetin with TMZ + LMP744 in glioma (NCT07025226) — senolytics as adjuvant sensitizer.
- Responder enrichment: SASP-score / p16+ T-cell burden predicts D+Q response (higher burden = greater benefit) — the personalization wedge.
- Market projections: senolytic drugs ~$2.8B (2025) → ~$9.6B by 2034; ophthalmology leads applications. No FDA approval yet; class-first approval plausible ~2030 in ocular niche via foselutoclax-line agents.
2026 Q3/Q4 Developments
- Foselutoclax 36-week data — published Nov 2025: complete 36-week ASPIRE results were presented at AAO 2025 (Orlando, Oct 18–20 2025) and subsequently analyzed in coverage including Ophthalmology Times' Nov 2025 head-to-head discussion and HCPLive's UBX1325 Matches Aflibercept writeup. In anti-VEGF-refractory DME, foselutoclax + aflibercept yielded BCVA gains comparable to continued aflibercept alone (~+5.5 ETDRS letters at 36 weeks), with durable OCT structural benefit. The non-inferiority design (not superiority) means foselutoclax is being positioned as an adjunctive agent in DME rather than an aflibercept replacement. No Phase 3 registration is yet posted — UNITY's next move is widely awaited. Sources: ophthalmologytimes.com/view/aao-2025-the-aspire-phase-2b-trial-of-ubx1325-head-to-head-against-aflibercept; hcplive.com/view/ubx1325-matches-aflibercept-in-vision-gains-for-dme-at-36-weeks; ophthalmologyadvisor.com/reports/foselutoclax-ubx1325-durable-vision-benefits-diabetic-macular-edema (Nov 10 2025).
- Fisetin — MDPI 2026 review: "Clinical Translation of Fisetin for Age-Related Diseases: Current Evidence and Future Opportunities" (Nutrients 18(18):2999, 2026). Consolidates the broad preclinical promise against the still-thin human evidence base; fisetin retains the strongest safety profile in the senolytic class but the most urgent question — does it meaningfully clear p16⁺/SA-β-gal⁺ cells in humans at achievable oral doses — remains incompletely answered.
- Fisetin — vascular function trial (Fisetin to Improve Vascular Function in Older Adults, NCT06133634): separate from NCT06431932 (multimorbidity pilot); aimed at endothelial function as a clinically meaningful peripheral readout. Status: enrolling as of late 2025.
- Preprints.org 2026 (manuscript 202607.1685): "Effects of Two Fisetin Dosing Regimens on Reducing Senescence-Related Genes in PBMCs in Aged Humans" — preliminary dosing-finding work intended to address the central PK/efficacy gap (fisetin has low oral bioavailability; senolytic relevance of achievable plasma concentrations is debated).
- AFIRA-style frailty / functional endpoints: the AFIRA (Alleviation of Frailty, Inflammation, and Related Disorders) trial concept continues to be developed as a candidate pivotal design for systemic senolytic registration — no completion date yet.
Evidence Separation
Human (emerging Tier 2): D+Q pilots (DKD, IPF, bone); intermittent dosing 3 days/month; foselutoclax Ph2b in DME. Responder enrichment improves interpretability.
Animal/In-vitro: robust clearance of senescent cells, SASP reduction, tissue rejuvenation across models (kidney, heart, disc, brain — mixed by model).
Limitations: small n; dosing/frequency not standardized; fisetin human efficacy data thin; systemic BCL-family inhibitors still toxicity-limited; no mortality/hard-endpoint human data.
Competitive Landscape vs Other Longevity Modalities
- Vs. rapamycin/mTORi: senolytics may avoid exercise blunting (RAPA-EX-01 caution applies to rapamycin, not D+Q); mechanism complementary (clearance vs. signaling).
- Vs. NAD+/reprogramming: orthogonal mechanisms; stacking rationale exists but zero human combination data.
- Clinic claims audit: off-label D+Q/fisetin sold by longevity clinics ahead of evidence — "clears zombie cells" marketing overstates Tier-2 pilot data.
Wikilinks
- 11 - Longevity and Anti-Aging/Senolytics
- 11 - Longevity and Anti-Aging/Rapamycin Dosing Protocols
- 01 - Peptides/Rapamycin mTOR Inhibition - PEARL Trial Evidence
- 11 - Longevity and Anti-Aging/SGLT2 Inhibitors as Senotherapeutics
- 09 - Human Biology Optimization/Urolithin A - Mitophagy Inducer
10Connections
11Sources
- PubMed 28196122PubMed 28196122
- NCT02848131NCT02848131
- NCT04338035NCT04338035
- Zhu Y, et al. (2017). "Identification of Senolytic Agents that Selectively Clear Senescent Human Cells." Aging Cell . PMID: 28777267PubMed 28777267
- Justice JN, et al. (2019). "Senolytics in Idiopathic Pulmonary Fibrosis." EBioMedicine . PMID: 30945520PubMed 30945520
- Xu M, et al. (2018). "Senolytics Improve Physical Function and Increase Lifespan in Old Age." Nat Med . PMID: 30279175PubMed 30279175
- Hickson LJ, et al. (2019). "Senolytics Decrease Senescent Cells in Humans." Aging Cell . PMID: 31433972PubMed 31433972
- Kirkland JL, Tchkonia T. (2020). "Senolytic Drugs: From Discovery to Translation." Nat Rev Drug Discov . PMID: 34508979PubMed 34508979
- PubMed 31542391PubMed 31542391
- PMC6796530PMC6796530
- NCT04313634NCT04313634
- NCT04685590NCT04685590
- PMC11433175PMC11433175
- PubMed 41985884PubMed 41985884
- NCT04733534NCT04733534
- NCT07025226NCT07025226
- NCT06133634NCT06133634
- NCT06431932NCT06431932
12Entry history
Latest content update.
Folded in 1 earlier page: senolytic-therapeutics-clinical-translation.
Heretic informs and never prescribes. Where amounts appear, they describe what published studies used. Talk to a qualified clinician before acting on anything here.