They also cause development of female sex characteristics such as full breasts, fat deposition of hips, and well-lubricated vaginal mucosa. During pregnancy, it is made in ever-increasing amounts by the placenta.
Progesterone is the hormone that promotes gestation .
It also has many beneficial effects throughout the body, including the brain, nerve cells and myelin sheaths, the adrenal glands, the testes, the prostate, the immune system, on energy production, on utilization of thyroid hormone, on cell membranes, in fat metabolism, in moisturizing the skin and mucous membranes, and in preventing cancer, to name but a few. It is a mistake to think of it as a sex hormone. Progestin is the name given to chemical analogs of progesterone that also can hold in the proliferative endometrium but do not have the same benefits to the embryo or all the other aspects of natural progesterone. They are commonly used in birth control pills and mistakenly given to postmenopausal women in place of natural progesterone. The progesterone revolution refers to the change in medical and societal thinking regarding hormone balancing, hormone replacement therapy, and recognition of the dangers of unopposed estrogen.