As the percentage of senior citizens increases at the present time, the purpose of the present invention is to provide a cosmetic which can maintain the skin in a healthy state by preventing damage to the skin that accompanies aging, more specifically, discoloration and wrinkling, is very safe, does not pose ethical problems, and can be supplied in a sufficient amount. The present invention provides a cosmetic that comprises as the main component a powder of the supernatant produced by culturing the bone marrow or dental pulp stem cells of a nonhuman mammal. Moreover, provided is a method for ion introduction for protein by which the cosmetic is introduced by ion introduction.