Azelaic Acid is a naturally occurring chemical belonging to the class of dicarboxylic acids. In skin care, it is most commonly used to treat acne. However, azelaic acid also reduces melanin production by inhibiting (largely indirectly) the enzyme tyrosinase. It also suppresses the proliferation of abnormal melanin producing cells (melanocytes), apparently by reducing the rate of DNA synthesis. Azelaic acid has been used to treat melasma, lentigo maligna and other hyperpigmentation problems. Topical azelaic acid has no or little depigmentation effect on normally pigmented skin, freckles, age spots (solar lentigines), and nevi. It is widely used in cosmetics and pharmaceuticals