Azelaic Acid Gel, is a commonly used clinical dermatology medication, which is helpful in the lightening of hyperpigmentation left behind by mild to moderate inflammatory acne vulgaris. Azelaic acid gel, in which the main ingredient is azelaic acid, can be given in conjunction with a doctor’s advice for mild to moderate acne. Melanosis is considered to be related to heredity, sun exposure, endocrine, metabolism, tumors, inflammatory diseases, physical and chemical stimuli and congenital factors, which may lead to the deepening of the local skin color, which can occur in any part of the body, and will be accompanied by different symptoms. It is recommended not to use drugs blindly, you can go to the hospital dermatology department for examination to find the cause of pigmentation. By removing the triggers and treating the primary disease, it can help to improve. If necessary, the pigmentation can be removed by topical medication and laser irradiation. The use of medication needs to be carried out under the guidance of a doctor, changes in the properties of the drug are prohibited, and allergies to the ingredients inside the drug are prohibited. Before using the drug, you should also read the instructions in detail to understand the adverse effects of the drug.