How is Urea present in normal skin?
Urea is an essential NMF in skin along with epidermal lipids and proteins, all of which are produced during the keratinisation process. It gets into the horny layer as an end product of the decomposition of the amino acid, arginine (a building block in proteins), during the keratinisation process. Urea represents 7% of the NMF in the horny layer.