For decades, aging was treated as an inevitable, untreatable process. That view is shifting fast. A growing field of geroscience research now focuses on the biological drivers of aging itself — and one of the most discussed targets is a population of damaged cells nicknamed “zombie cells.” A new class of compounds called senolytics aims to clear them out. Early human trials are underway, and the results, while preliminary, are intriguing enough that the National Institute on Aging has funded a multi-year program to test the approach.
What does the science actually show, and should anyone be experimenting with senolytics today? Here is what current research suggests.
What are “zombie cells”?
Cellular senescence is a state cells enter after damage from radiation, oxidative stress, or repeated division. A senescent cell stops dividing but does not die. Instead, it lingers in tissue and releases a cocktail of inflammatory signals, growth factors, and tissue-degrading enzymes — a phenomenon scientists call the senescence-associated secretory phenotype, or SASP.
In small numbers, senescent cells appear to serve a useful purpose, contributing to wound healing and tumor suppression. The problem, according to research published in Nature and other journals, is that they accumulate with age and overwhelm the body’s ability to clear them. The chronic, low-grade inflammation they produce — sometimes called “inflammaging” — has been linked to osteoarthritis, cardiovascular disease, type 2 diabetes, Alzheimer’s disease, and frailty.
In a landmark 2016 study from the Mayo Clinic, researchers genetically engineered mice to eliminate their own senescent cells. The treated mice lived 25 to 30 percent longer than controls, with healthier hearts, kidneys, and fat tissue. That experiment helped launch the modern senolytics field.
How senolytics work
Senolytics are drugs or natural compounds that selectively kill senescent cells while leaving healthy cells largely alone. They exploit the fact that senescent cells depend on specific survival pathways — particularly anti-apoptotic proteins like BCL-2 and BCL-XL — to resist their own death. Block those pathways, and the cell self-destructs.
The most studied senolytic combination is dasatinib (a cancer drug) paired with quercetin (a plant flavonoid found in onions, apples, and capers). Researchers refer to it as D+Q. Other candidates include fisetin (a flavonoid concentrated in strawberries), navitoclax, and several investigational small molecules.
What human trials have shown so far
Most senolytic data still come from animal studies, but human research has begun. A 2019 first-in-human pilot trial published in EBioMedicine tested D+Q in 14 patients with idiopathic pulmonary fibrosis, a fatal lung disease driven in part by senescent cells. After three weeks, participants showed measurable improvements in physical function — walking distance, chair-rise speed, and grip strength — though the trial was small and lacked a placebo arm.
A 2019 study in EBioMedicine on patients with diabetic kidney disease reported that D+Q reduced markers of senescence in fat and skin tissue. A 2024 trial published in Nature Medicine tested a different senolytic candidate in older adults with mild cognitive impairment, with researchers reporting changes in inflammatory biomarkers and tolerability of the regimen, though clinical benefit remains to be established in larger studies.
The U.S. National Institute on Aging is currently funding the Translational Geroscience Network, a consortium running placebo-controlled trials of senolytics in conditions including Alzheimer’s disease, osteoarthritis, and post-COVID fatigue. Most are still in Phase 1 or Phase 2.
The natural senolytics question
Because quercetin and fisetin are sold as dietary supplements, public interest in “natural senolytics” has surged. The research picture is more nuanced than supplement marketing suggests.
Fisetin, in particular, performed strongly in mouse studies from the Mayo Clinic group, reducing senescence markers and extending median lifespan in older animals. A 2018 paper in EBioMedicine called fisetin one of the most potent natural senolytic compounds tested. Human trials are ongoing, including an Alzheimer’s disease study and a frailty study.
Quercetin alone is a less effective senolytic than the D+Q combination in laboratory models, but it contributes meaningfully when paired with dasatinib. Sulforaphane (from cruciferous vegetables), luteolin, and curcumin have shown senolytic-like activity in some assays, though clinical evidence is limited.
Standard supplement doses of quercetin or fisetin used for everyday antioxidant support are typically far lower than the experimental “hit-and-run” doses studied in trials, where compounds are taken at high levels for short intervals and then stopped. Whether lower daily doses meaningfully clear senescent cells in humans is unresolved.
Risks and unknowns
Senolytics are not without concerns. Dasatinib is an FDA-approved leukemia drug with well-documented side effects, including fluid retention, bleeding risk, and heart effects. Using it off-label for healthy aging is not recommended outside research settings.
Beyond drug safety, biologists are still debating which senescent cells matter most, when in life to target them, and whether removing them too aggressively could compromise tissue repair. Some senescent cells appear protective in early wound healing and may help suppress cancer initiation; eliminating them indiscriminately could backfire.
There is also a placebo and selection-bias risk: many early senolytic studies are small, open-label, and conducted in carefully chosen patient populations. Larger randomized trials are essential before any clinical claims can be made.
Lifestyle factors that influence senescent cell burden
While the pharmacology is being worked out, several lifestyle factors appear to modulate cellular senescence based on current evidence:
- Regular physical activity. Exercise has been shown in human studies to lower markers of senescence in muscle and adipose tissue.
- Caloric restriction and intermittent fasting. Animal models consistently show reduced senescent cell accumulation with reduced energy intake, though human evidence is still emerging.
- Sleep quality. Chronic sleep disruption is associated with elevated inflammatory markers that overlap with the SASP.
- A whole-food, plant-forward diet. Diets rich in polyphenols, fiber, and omega-3 fatty acids are associated with lower inflammaging.
- Avoiding chronic stressors. Smoking, excess alcohol, and untreated chronic infections all accelerate senescent cell buildup in tissue.
The bottom line
Senolytics represent one of the most promising directions in aging biology, but the field is still young. Research suggests that selectively clearing senescent cells could improve markers of healthspan, and a handful of small human trials show early signals worth confirming. The leap from those results to a proven anti-aging therapy is significant, and self-experimentation with off-label drugs or high-dose supplements carries real risk.
For now, the most evidence-backed strategy for managing the biology of aging remains the unglamorous one: regular movement, quality sleep, a diverse plant-forward diet, social connection, and routine medical care. Anyone considering senolytic supplements or off-label drug use should discuss the choice with a qualified healthcare provider.
Disclosure: This content is for informational purposes only and is not medical advice. Always consult a qualified healthcare provider before making changes to your health regimen.