What is described as a substance applied to alter the appearance of the face, skin, hair, or nails?

The term that fits the description of a substance applied to alter the appearance of the face, skin, hair, or nails is cosmetics. Cosmetics encompass a wide range of products that are specifically designed to enhance beauty or improve the aesthetic appeal of the body. This includes items like foundations, lipsticks, eyeshadows, skincare products, and hair dyes—essentially anything that is used for beautification purposes.

In contrast, medication typically refers to substances used for treating physiological or psychological conditions, not primarily for modifying appearance. Dermatological treatments may focus on skin health and diseases rather than altering appearance as the main goal. Aromatherapy products are intended for therapeutic benefits through scent, typically using essential oils, rather than for cosmetic purposes.