Different laws and regulations apply to each type of product. Some
products must comply with the requirements for both cosmetics and drugs. This happens when a product has two
intended uses, such as an antidandruff shampoo. A shampoo is a cosmetic because it is intended to clean hair.
An antidandruff shampoo is a cosmetic and a drug because it is intended to treat dandruff (which affects the
follicles where the hair is formed) and clean hair.
Warning letters issued by the FDA recently to firms that marketed hair
care products with claims such as restoration of hair growth and hair loss prevention illustrate an important
distinction between the legal definitions of cosmetics and drugs. Warning letters officially inform companies
that they may be engaged in illegal activities, and instruct manufacturers on how to bring their products
into compliance with the law. Hair growers and hair loss prevention products, because of their mechanism of
action, are considered drugs, not cosmetics, and these firms were not meeting the legal requirements for
marketing a drug.