Progesterone is a female hormone that plays an important role in the menstrual cycle and during pregnancy. It plays a balancing role with estrogen, and if not present in adequate amounts in the body, may predispose a woman to certain types of breast and uterine cancer. With the onset of menopause, the ovaries produce less progesterone.

Progesterone is not absorbed well when taken by mouth, but is absorbed reasonably well when applied to the skin. This has led to the development of a number of Progesterone Creams. Some contain synthetic progesterone, others contain natural Progesterone extracted from plants like the yam, and a third group of creams combines synthetic and natural progesterone. Natural Progesterone is widely thought to be safer than synthetic Progesterone compounds; however, scientists consider both natural and synthetic Progesterone to be equally safe and effective. Another fallacy is that natural Progesterone is effective in humans. Plant extracts contain a precursor of Progesterone called diosgenin, which can only be metabolized into active Progesterone by plants themselves. Many cream manufacturers combine plant extracts with synthetic progesterone, while still claiming their products contain