Few physicians consider cosmetics and related products relevant to their professional lives. Cosmetics, of course, are used to alter the body’s appearance, not its actual structure or function. However, the distinction between substances that only alter bodily appearance or aesthetics and medicinal compounds that affect the body’s structure or health (eg, wrinkle removal; prevention of gingivitis) is one the cosmetics industry and the US Food and Drug Administration (FDA) have struggled with for decades. As Paracelsus, the 16th-century Swiss physician and philosopher, observed, any substance applied to or in the body can cause harm, given the right circumstances.