This study aims to explore the impact of aging on skin elasticity, a key biomechanical property that diminishes over time, using the Cutometer to assess viscoelastic parameters. Methods: Researchers analyzed 22 viscoelastic parameters from the facial skin of 60 women aged 18 to 70. Key Results: The findings indicate that relaxation phase parameters, particularly biological elasticity (R7), exhibited the strongest negative correlation with age (r = −0.62), signifying a notable decline in biological elasticity as women age. In contrast, maximum deformation during the first cycle (R0) and the total area under the upper curve after 10 cycles of deformation (F4) also showed significant negative correlations with age (r = −0.47, r = −0.48), suggesting that younger skin typically presents higher values. These correlations raise questions regarding practical applications, as the presence of moisturizers and emollients may alter the stratum corneum’s properties, thus impacting these measurements. Additionally, the ratio of delayed deformation to instantaneous deformation (R6) demonstrated a positive correlation with age (r = 0.49), indicating its potential as a marker for skin aging. Conclusions: This study highlights the critical role of relaxation phase parameters in accurately reflecting skin elasticity changes associated with aging. The results offer valuable insights for evaluating cosmetic efficacy, reinforcing the need for a nuanced understanding of how various parameters interact. These findings contribute to the ongoing development of more effective anti-aging treatments and products.

Skin hyperpigmentation and ultraviolet (UV)-induced photodamage represent prevalent cosmetic concerns that demand safe and effective topical intervention strategies. This study evaluated the skin-whitening, pigmentation-improving, and post-UV repair efficacy of a novel dual-compartment sheet mask (DCSM) formulated with eight complementary depigmenting ingredients, namely niacinamide, α-arbutin, glabridin, hexylresorcinol, ascorbyl tetraisopalmitate (VC-IP), paeonol, Camellia japonica flower extract and Ormosia henryi bark extract, through two independent human efficacy studies and in vitro cell experiments. In a 28-day, self-controlled human efficacy study (Cohort 1; n = 32), regular DCSM use was associated with significant increases in the individual typology angle (ITA), significant decreases in the b* value, significant reductions in H-channel standard deviation (H-SD), significant decreases in the melanin index (MI), and significant diminishment of pigment spot area and optical density, suggesting progressive and sustained improvements in skin tone, uniformity, and pigmentation. In a separate UV-induced skin erythema model (Cohort 2; n = 30), seven days of daily DCSM application significantly attenuated UV-induced increases in MI, erythema index (EI), and a* value while promoting recovery of skin lightness (ITA) relative to untreated control sites, indicating effective post-sun erythema alleviation and pigmentation suppression. In vitro, treatment of α-MSH-stimulated A-875 human melanoma cells with 5% (v/v) DCSM emulsion significantly suppressed intracellular melanin synthesis at a non-cytotoxic concentration, providing supportive evidence consistent with the human efficacy findings observed in vivo. Collectively, these multidimensional findings indicate that DCSM use was associated with improvements in skin hyperpigmentation, an even skin tone, and facilitated recovery from UV-induced photodamage, supporting its potential as a cosmetic intervention for pigmentation regulation and post-sun skin repair.