The Cosmelan Peel Conquers Melasma! A topical in-office cream peeling agent is applied to your skin and left on for the day. You will peel, similar to a peel after a sun burn. At home products further reduce the pigment levels and help suppress the development of new pigment. The Cosmelan Mask works by blocking the process that causes hyperpigmentation. It works for Melasma, Brown spots, blotchy skin, hyperpigmentation, Post inflammatory hyperpigmentation, prevention of hyperpigmentation post-laser and post-peel.