What is Fisetin?

Fisetin is a plant flavonol and polyphenol found in small amounts in strawberries, apples, onions, grapes, and cucumbers. It has attracted significant interest in aging research for its ability to modulate senescence-related signaling, support antioxidant defenses, and extend lifespan in preclinical models. Fisetin is one of the 12 ingredients in NOVOS Core. It has attracted interest in aging research because preclinical studies (cell and animal) show fisetin has antioxidant activity and can modulate inflammatory signaling, stress-response pathways, and markers associated with cellular senescence. Preclinical mouse studies also report improved measures of health and lifespan extension when fisetin is given later in life. However, these findings are primarily preclinical, and it is not yet established that fisetin clears senescent cells or produces longevity benefits in humans.

How Fisetin Supports Healthy Aging: Key Mechanisms

• Cellular senescence
• Altered intercellular communication
• Loss of proteostasis
• Nutrient-sensing/metabolic signaling
• Cell-cycle and apoptosis-related gene programs

Exploring the connection between fisetin and our golden years.

Fisetin is a flavonoid, a broad class of plant polyphenols. Flavonoids include many compounds that help plants respond to environmental stress, and some also contribute to the bright colors of fruits and vegetables. In human biology, flavonoids are studied not only for antioxidant activity in laboratory settings, but also because they can influence cellular signaling pathways involved in stress responses and inflammation.

Like most polyphenols, fisetin has low water solubility and undergoes extensive metabolism after oral intake. Taking fisetin with a fat-containing meal may support absorption. When evaluating fisetin supplement quality, consider both the dosage and how the supplement is formulated, as these factors affect how much active fisetin reaches tissues.

Fisetin and Cellular Senescence: What the Research Shows

Fisetin is widely studied for its effects on cellular senescence, a process in which damaged cells permanently stop dividing but do not undergo programmed cell death. Senescent cells accumulate in many tissues with age and contribute to age-related dysfunction.

Unlike most damaged cells that are removed, senescent cells can linger. They release many chemical signals, often called the SASP, that can drive inflammation, weaken the tissue “scaffolding” around cells, and interfere with the function of nearby healthy cells.

Preclinical studies (cell and animal models) suggest that fisetin can reduce markers of senescent cell burden and modulate senescence-associated signaling in certain tissues. Through these effects, fisetin has been associated with reduced inflammation-related signaling and improved tissue function in aging models. However, it has not been established that fisetin selectively clears senescent cells or produces senolytic effects in humans (R).

Senescent cells are also known to interfere with stem cell function, limiting the body’s ability to repair and regenerate tissues. In animal models, reducing senescence-associated signaling has been linked to improvements in stem cell activity and tissue maintenance, though the relevance of these findings to human aging remains under investigation.

Compounds that can selectively target senescent cells are referred to as senolytics. Fisetin is best described as a senotherapeutic candidate with senolytic-like effects reported in preclinical research. While fisetin has demonstrated cytotoxic effects in cancer cell lines in laboratory studies, these findings do not establish cancer prevention or treatment effects in humans (R).

Fisetin vs Quercetin: Which Is Better for Senescence?

Fisetin and quercetin are naturally occurring flavonoids that have been studied for their effects on cellular senescence in preclinical research. Although they share some structural similarities, their biological effects can differ depending on the cell type, dose, and experimental model.

In a well-cited cell-based screening experiment, fisetin showed the strongest reduction in senescent cell markers among several tested compounds, including quercetin, curcumin, and EGCG. These are in vitro results from cultured cells and do not establish the same effects in humans, but they highlight fisetin as the leading compound in this experimental comparison and explain its prominence in longevity supplement research (R):

In this assay, fisetin reduced the relative number of senescent cells more than any other compound, while having a comparatively smaller effect on total cell number. This profile suggests a more pronounced senotherapeutic effect under the specific conditions of the experiment.

These results come from in vitro studies and reflect outcomes in cultured cells under controlled conditions. While they do not establish effects in humans, they clearly highlight fisetin as a leading compound in this experimental comparison, which is why it has received significant attention in aging research.

Fisetin Longevity Research: Lifespan Extension Across Species

Fisetin has been evaluated in several well-established lifespan models, where it has been shown to extend lifespan under specific experimental conditions. Across these studies, fisetin increased lifespan in evolutionarily diverse organisms, supporting its relevance in aging research.

In yeast (Saccharomyces cerevisiae), fisetin increased replicative lifespan by approximately 55%, as reported in early longevity studies (R). In fruit flies (Drosophila melanogaster), fisetin supplementation extended lifespan by about 23% (R). In nematodes (Caenorhabditis elegans), fisetin increased mean lifespan by approximately 10%, based on reported survival data (R).

In mice, fisetin supplementation initiated late in life was associated with approximately 17% longer median lifespan in a well-characterised study, as quantified by the DrugAge database. Notably, the intervention began at an advanced age, demonstrating that fisetin can influence survival outcomes even when introduced late in the lifespan. These are animal study findings and do not establish equivalent effects in humans. This finding is notable because the intervention began at an advanced age, demonstrating that fisetin can influence survival even when introduced late in the lifespan (R).

Fisetin Benefits for Skin, Inflammation, and Oxidative Stress

Beyond its role in senescence research, fisetin has been studied across several aging-related pathways. Preclinical research suggests fisetin modulates inflammatory signaling (including NF-kB), supports antioxidant defenses such as glutathione, and influences Akt/mTOR-related pathways involved in cell growth and nutrient sensing, all mechanisms relevant to the biology of aging. (R)

Inflammation

In multiple laboratory studies, fisetin has been shown to dial down inflammatory signaling, including effects on a key inflammation “switch” called NF-κB, and to reduce the production of inflammatory messengers in experimental models (R ,R)

Oxidative stress

Fisetin is also studied for its ability to help cells handle oxidative stress. In cell models (including nerve-cell–relevant systems), fisetin supported natural antioxidant defenses, such as increasing glutathione, one of the body’s major internal antioxidants, and helped protect cells under stress conditions (R).

Cell growth and metabolism signaling

Finally, fisetin has been studied in pathways that control cell growth and metabolism. In certain cell studies, fisetin affected Akt/mTOR-related signaling, a set of pathways often discussed in aging biology because they help regulate growth, nutrient sensing, and stress responses (R, R).

NOVOS CORE & Fisetin