Skin aging is a complex, multifactorial process that is significantly influenced by ultraviolet (UV) radiation. This radiation induces the generation of reactive oxygen species (ROS), leading to collagen degradation and ultimately resulting in wrinkle formation. Soybean seed extract has been the subject of extensive research due to its antioxidant, antiproliferative, and anticancer properties. In the present study, alkaline hydrolysates derived from soybean were evaluated using the biuret test, ash content analysis, Fourier-transform infrared (FTIR) spectroscopy, and the DPPH antioxidant activity assay. The antimicrobial effect of the samples was also assessed by determining the minimum inhibitory concentration (MIC). In addition, the impact of soybean hydrolysates on the viability and proliferation of murine L929 fibroblast cells, as well as their protective role against oxidative stress induced by hydrogen peroxide (as an induced aging model), were investigated using the MTT assay. The findings indicated that alkaline soybean hydrolysates are rich in proteinaceous compounds and possess high antioxidant capacity, yet exhibit no inhibitory effect on microbial growth (based on the MIC test). Evaluation of these hydrolysates on healthy cells revealed a significant increase in proliferation across all tested concentrations. Furthermore, MTT results on hydrogen peroxide‑induced senescent fibroblasts demonstrated the highest protective effect at a dilution of 1:64, while the weakest protection was observed at 1:8. Overall, it can be concluded that soy protein hydrolysate, at an appropriate concentration, may serve as a natural and safe compound for use in cosmetic and personal care products, with the aim of providing cellular protection against oxidative aging.