Hair color changes caused by drugs are not a prevalent side effect. A wide range of medicines have been linked to hair color changes, although few few have data to back up a definite link. Commonly reported side effects include color change of the skin around the nose, mouth, or eyes; dry skin; increased risk of infection; problems with vision; and weight gain. There are two main types of drug-induced hair color changes: hyperpigmentation and depigmentation. Hyperpigmentation refers to the development of dark spots on the skin or mucous membranes due to the increase in pigment within melanocytes. This can occur anywhere on the body but is most common on the hands, feet, face, and neck. The cause is often unknown but may be related to sunlight exposure, age, gender, ethnicity, genetics, and/or underlying medical conditions. It is usually temporary but may become permanent if not treated. Depigmentation occurs when there is loss of pigment from the skin or mucous membranes. This is usually due to damage or death of melanocytes (cells that produce pigment) but can also be caused by medications such as hydroquinone (Cognisant) and kojic acid (Fluka). Depigmentation can lead to white patches under the skin or inside your mouth, tongue, or gut.