Certain vitamins and antioxidants have great popularity as primary ingredients in cosmetics. The magnesium salt of ascorbyl-2-phosphate (MAP) has been widely used as antioxidant and collagen promoting ingredient in cosmetic formulations. Melatonin (MELA) is known to be a potent antioxidant in vitro and in vivo. In this study we investigated the effect of the addition of melatonin to a MAP-containing formulation on the mechanical properties of human skin. A total of 10 healthy women aged 37-47 years, of phototype III and IV were studied. The MAP-MELA formulation was applied topically on the one side of the face twice daily for three weeks. The MAP formulation was applied on the other side of the face twice daily for the same period of time. The forehead was used as the untreated control area. Gross elasticity (Ua/Uf: 11.9%, p<0.05) and biological elasticity (Ur/Uf: 15.2%, p<0.005) were significantly improved for the MAP treated area. However topical application of MAP-MELA cream led to higher increase of these two elastic parameters (Ua/Uf: 16.7%, p<0.05) and (Ur/Uf: 23.7%, p<0.005). Regarding to viscoelastic to elastic ratio (Uv/Ue) a slightly higher increase was observed in the case of MAP-MELA treated site (11.4, p<0.005) in comparison with the MAP treated area (8.88 %, p<0.005).