A review of nicotinamide: treatment of skin diseases and potential side effects.

Nicotinamide, also known as niacinamide, is the amide form of vitamin B3. It is a precursor of essential coenzymes for numerous reactions in the body including adenosine triphosphate (ATP) production. Nicotinic acid, also known as niacin, is converted into nicotinamide in the body. The use of topical nicotinamide in the treatment of acne vulgaris; melasma; atopic dermatitis; rosacea; and oral nicotinamide in preventing nonmelanoma skin cancer is discussed. The possible side effects and consequences of excessive nicotinamide exposure are reviewed, including suggestions nicotinamide might have a role in the development of diabetes, Parkinson's disease, and liver damage.