<p>This pilot study aimed to evaluate the impact of a diet supplemented with potential geroprotectors on metabolic and aging‐associated markers in domestic cats. A total of 53 adult domestic cats were randomly assigned into two groups: a control diet (CD) and a geroprotective diet (GD) containing five plant-based extracts (silymarin, green tea, grape seed, curcumin, and grapefruit seed). Animals were fed the respective diets for three months. Body weight and body condition score were recorded before and after the feeding period. Blood samples were analyzed for standard biochemical parameters. Peripheral blood mononuclear cells were isolated to assess the expression of markers associated with inflammation (NF-κB, IL-1β), senescence (p16), and metabolic regulation (SIRT1, Klotho, RAGE) by Western blot. Both diets supported adequate body weight and condition. The GD group demonstrated a significant reduction in serum creatinine and a marked decrease in inflammatory and senescence markers (lower RAGE, p16, phospho-NF-κB) compared to baseline. SIRT1 levels were significantly upregulated only in the GD group, suggesting a possible protective mechanism against age-related changes. These data reveal a mechanistic link between dietary geroprotector supplementation and the modulation of key molecular hallmarks of aging in felines, highlighting conserved pathways of aging across mammalian species and establishing a foundation for translational interventions targeting age-associated decline in companion animals. Further long-term and larger-scale studies are required to confirm and extend these observations.</p>