The Federal Food, Drug, and Cosmetic Act (FD&C Act) defines cosmetics, in part, by their intended use, as "articles intended to be rubbed, poured, sprinkled, or sprayed on, introduced into, or otherwise applied to the human body...for cleansing, beautifying, promoting attractiveness, or altering the appearance" (FD&C Act, sec. 201(i)). The FD&C Act defines drugs, in part, by their intended use, as "articles intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease" and "articles (other than food) intended to affect the structure or any function of the body of man or other animals" (FD&C Act, sec. 201(g)(1)). Some skin care products are regulated as cosmetics. Others are regulated as drugs, or as combination drug-cosmetic products. For example, acne treatments, dandruff treatments, and skin protectants are regulated as drugs. A cleanser that is also an acne treatment, or a shampoo that is also a dandruff treatment is regulated as a combination drug-cosmetic. The requirements for cosmetics and drugs are different. Products that are both drugs and cosmetics must meet the requirements for both categories.
For more information on this subject, please see "Is It a Cosmetic, a Drug, or Both? (Or Is It Soap?)."