An object of the present invention is to provide a moisturizer that can sufficiently promote the production of moisturizing-related proteins and can achieve sufficient moisturizing effect. In other words, the present invention provides a moisturizer including an acyl neutral amino acid involving an acyl group having a carbon atom number of 2 to 18 or a salt thereof, and a cosmetic including the moisturizer. The moisturizer and the cosmetic of the present invention can promote the production of one or more moisturizing-related proteins selected from the group consisting of filaggrin, involucrin, transglutaminase 1, keratin 10, and loricrin.
