Natural killer (NK) cells produce various cytokines, including interleukin (IL)‑1β, IL‑6, IL‑10, IL‑12, interferon γ, tumor necrosis factor α and transforming growth factor β, which are critical in modulating immune responses. NK cell‑conditioned medium (NK‑CdM), rich in cytokines, has potential applications in therapy and healing. The present study aimed to investigate the protective effect of NK‑CdM against ultraviolet B (UVB)‑mediated photoaging using