A reconstructed epidermis/skin equivalent supplemented with at least one ceramide 7 and/or 5.5 compound, suited for reinforcing the barrier function of normal human epidermis and for improving the barrier function of dry skin and of reconstructed skin or skin equivalents, is prepared by introducing the at least one ceramide 7 and/or 5.5 compound into the culture medium of such reconstructed epidermis/skin equivalent and/or topically applying onto the face surface of such reconstructed epidermis/skin equivalent a composition which comprises lipid lamellar vesicles incorporating at least one ceramide 7 and/or 5.5 compound.