Calcitonins are used to treat osteoporosis in females who've gone through menopause, Paget's disease of bone, and hypercalcemia (high calcium levels in the blood). They work by inhibiting the activity of osteoclasts, the cells that break down bone, which helps to maintain bone density and lower calcium levels in the blood. Examples include calcitonin salmon (Miacalcin) injection and calcitonin salmon nasal spray.