The present invention relates to the activation of peptidyl arginine deiminase (PADs) 1 and/or 3 in the epidermis by at least one active agent used alone or in combination, namely caffeine, acefylline and/or theobromine in a cosmetic and/or pharmaceutical composition. The present invention also relates to the use of the aforementioned active agents in cosmetics and/or therapeutics, alone or in combination, in order to improve the barrier functions of the epidermis, to prevent and/or treat symptoms related to dry skin or to improve and/or promote hydration of the keratinous layer. Finally, the invention relates to increasing the activity of PAD1 and/or PAD3 in the epidermis.
