Lactic acid breaks the protein junctions between the corneocytes, causing their detachment and reducing the thickness of the hyperkeratotic stratum corneum. It stimulates the production of collagen and glycosaminoglycans constituents of the dermal matrix. Also exerts a natural moisturizing effect on the skin by attracting water molecules to the horny layer and stimulating the synthesis of ceramides, improving and modulating the barrier function. It promotes homogenous dispersion of melanin, inhibits the action of tyrosinase and blocks melanogenesis. Has an antioxidant effect.
Mandelic acid has a bigger molecular structure than other AHAs so it penetrates more slowly into the stratum corneum and requires a longer exposure time. For this reason it does not cause irritation or pruritus on the skin. Further it increases collagen, elastin and glycosaminoglycans synthesis in the papillary dermis. Also exerts a depigmenting effect even in dark phototypes.