In vitro skin test panels provide a scientific and ethical approach to evaluating the efficacy and safety of dermatological and cosmetic products. Using reconstructed human epidermis (RHE) models like EPISKIN  these tests replicate the structural and functional characteristics of human skin, allowing for accurate and reliable assessments. Key applications include skin irritation and corrosion testing, which evaluate cell viability and barrier integrity, and anti-aging efficacy studies that measure biomarkers like collagen and elastin to assess wrinkle reduction and skin firmness. Additionally, skin sensitization assays, such as h-CLAT, predict immune response potential, while skin penetration studies analyze the absorption and bioavailability of active ingredients. These in vitro methods are reproducible, cost-effective, and compliant with regulatory standards, making them essential for modern cosmetic and pharmaceutical research.