Melanin is produced by specialized epidermal cells called melanophores (or melanocytes). Their dispersion in these cells is controlled by melanocyte - stimulating hormone and melatonin. Melanin, a pigment present in skin, protects it from harmful effects of UV rays. People living in tropics have more melanin in their skin which is an adaptation to protect themselves from harmful UV rays. Melanin cannot protect from infrared rays and X-rays.