Progesterone

Progesterone is a term that is incorrectly used interchangeably to describe both natural bio-identical progesterone and synthetic derivatives. Synthetic progestins (also called progestogens or progestational agents) are analogues of bio-identical progesterone, and have been developed because they are patentable, more potent, and have a longer duration. Medroxyprogesterone acetate, the most commonly used synthetic progestin, was shown in a large study to cause significant lowering of HDL "good" cholesterol, thereby decreasing the cardioprotective benefit of estrogen therapy. Bio-identical progesterone has never been shown to have any serious side effects. However, progestins can have significant and serious side effects at typical doses, including migraine headache, weight gain, mood swings, depression, irritability, acne, menstrual irregularities, and fluid retention. These side effects are a frequent cause for discontinuation of HRT. Only about 20% of women who start synthetic HRT remain on it two years later.

Progesterone:

The benefits of progesterone are not limited to prevention of endometrial cancer in women who are receiving estrogen replacement. Progesterone therapy is not only needed by women who have an "intact uterus", but is also valuable for women who have had a hysterectomy. Vasomotor flushing is the most bothersome complaint of menopause, and is the most common reason women seek HRT and remain compliant. For over 40 years, estrogens have been the mainstay of treatment of hot flashes, but transdermal progesterone cream may be effective as well. Women who have had postpartum depression once have about a 68% chance of having it again after another pregnancy, but trials using prophylactic progesterone have shown that it is possible to reduce the recurrence rate to 7%. Other benefits include improved bone density and enhanced glucose utilization.