The subject matter of the present invention is a cosmetic or dermopharmaceutic composition comprising a combination of homarine and erythritol as well as a non-therapeutic treatment method of the skin to improve cutaneous hydration, to prevent and/or treat cutaneous dryness signs, to restore and/or protect the cutaneous barrier function, to protect cells of the skin and/or of the scalp from osmotic shocks, for example from UV induced osmotic shocks.