Progesterone has several important roles in women. It maintains a normal menstrual cycle and plays an important role during pregnancy by preparing the tissues lining the uterus for implantation by the fertilized egg. It also helps prepare the breasts for milk production. The growing fetus also uses Progesterone to produce steroid hormones that are essential for normal fetal development. Progesterone plays a protective role in preventing some breast and uterine cancers. It also stimulates normal bone growth and thyroid function. When given as a supplement, Progesterone can help initiate and maintain a pregnancy. Short-term Progesterone and estrogen replacement therapy can help minimize some of the distressing symptoms of menopause, such as hot flashes. Other uses of Progesterone are in the suppression of milk secretion following delivery, and in the treatment of certain endometrial cancers. Progesterone is also an intermediate compound in the biochemical pathways that lead to the production of other important hormones such as testosterone, estrogen and cortisol.