Do fisetin and quercetin clear old cells in people?

Small human trials show fisetin and quercetin lower markers of aged cells. Quercetin trims blood pressure a little; health gains are unclear.

Published October 2026

Short answer

Early human trials show lower markers of aged cells, and quercetin trims blood pressure a little. No trial yet shows these help health. Evidence grade C (Limited). Small open-label pilots and a few small randomised trials measuring cell and blood markers, plus meta-analyses of blood pressure; downgraded for small size and surrogate outcomes.

Key takeaways

In nine adults with diabetic kidney disease, three days of dasatinib plus quercetin lowered markers of senescent cells in fat and skin within 11 days; these are lab markers, not health outcomes [1].
In a pilot of 14 people with lung scarring, walking distance improved after three weeks of dasatinib plus quercetin, but the pilot had no control group [2].
In a placebo-controlled pilot of 12 people with lung scarring, physical function did not differ meaningfully from placebo, though the trial was too small to settle it [3].
Across pooled randomised trials, quercetin supplements lowered systolic blood pressure by about 3 mmHg; diastolic results were mixed [4][5].
Pooled trials of flavonoid supplements, a group that includes quercetin, found about a third fewer upper respiratory infections [6].

The short version

Fisetin and quercetin are dietary flavonoids, plant compounds [6]. Some researchers think they can clear senescent cells, old cells that stop dividing and release inflammatory signals [1]. In small human trials, a short course of dasatinib plus quercetin lowered markers of these cells [1]. Quercetin supplements also lower blood pressure by a small amount [4]. The trials so far were too small to show whether this helps health [3].

What the studies show

Clearing old cells. Nine adults with diabetic kidney disease took dasatinib and quercetin for three days. Within 11 days, markers of senescent cells in fat and skin fell, along with some inflammatory signals in the blood [1]. These are lab measures, not health outcomes.

Physical function in lung scarring. In an open-label pilot of 14 people with idiopathic pulmonary fibrosis, three weeks of dasatinib plus quercetin improved walking distance, walking speed and chair-stand time [2]. There was no control group. A placebo-controlled pilot of 12 people found no meaningful difference in physical function between the two groups, but it was too small to test this well [3].

Bone. In a phase 2 trial of 60 postmenopausal women, intermittent dasatinib plus quercetin did not change the main bone-breakdown marker overall [7]. In women with the most senescent cells, bone density at the radius rose by 2.7% in an exploratory analysis [7].

Early Alzheimer's. Five people with early Alzheimer's disease tolerated dasatinib and quercetin for 12 weeks. Cognitive scores did not change significantly [8].

Fisetin on its own. In a 12-week trial of 60 men with obesity, fisetin at 200 mg a day led to more weight loss than placebo, and body mass index fell significantly only in the group that also trained [9]. In a separate 12-week trial of 44 men with obesity, fisetin with training lowered several inflammation and insulin markers, with the largest changes in the fisetin-plus-training group [10].

Blood pressure. In meta-analyses of randomised trials, quercetin supplements lowered systolic blood pressure by about 3 mmHg [4][5]. An umbrella review put the systolic drop at 1.9 mmHg and found no change in diastolic pressure [11].

Colds. Pooled trials of flavonoid supplements found about one-third fewer upper respiratory infections than control groups [6]. Those trials pooled flavonoids in general, and the review called the sick-day result unclear. No quercetin-only cold trial turned up in our searches.

The nuances

The senolytic work is early. The diabetic kidney pilot was open-label, and Mayo Clinic holds patents on senolytic drugs with financial interests reported by several authors [1]. The human senolytic trials we found used dasatinib with quercetin rather than fisetin alone [1]. A phase 2 fisetin trial in breast cancer survivors is only a protocol so far, with results not yet available [12].

The blood pressure effect is small, and the diastolic results are inconsistent across reviews [11]. The fisetin weight trial describes its men as having obesity, but its entry criteria set BMI below 30 [9].

What this means for you

The blood pressure effect of quercetin is small, and it does not replace prescribed treatment [4]. Clearing old cells is still a research idea, and larger trials are needed before anyone can judge benefit [3]. If you take blood pressure medicine or any prescription drug, talk to a doctor before adding quercetin or fisetin. See the Fisetin and Quercetin page for doses and safety.

Go deeper

Fisetin and Quercetin — Quercetin supplements lower systolic blood pressure by about 2 to 3 mmHg in several meta-analyses of randomised trials.