Progesterone is one of two main hormones, the other being estrogen, that is made by the ovaries of menstruating women. When a woman s monthly cycle is functioning correctly, estrogen is the dominant hormone during the first two weeks of the menstrual cycle. In response to ovulation, progesterone assumes dominance for the final two weeks of the month. When the pituitary gland in the brain sends a message to the ovaries to stop production of progesterone, the menstrual cycle begins within 48 hours. Progesterone is also made in smaller amounts by the adrenal glands in both sexes and by the testes in males.
Progesterone is the precursor to estrogen, testosterone, and of all the important cortical hormones.
Progesterone is made from the sterol pregnenolone, which is in turn made from cholesterol, which is made from acetate, a product of the breakdown of sugar and fat in the body. From progesterone are derived not only the other sex hormones, including estrogen, but also the corticosteroids which are essential for stress response, sugar and electrolyte balance and blood pressure. Progesterone is essential for survival and its deficiency can cause a wide range of problems. Research by Dr. Lee has led him to describe the phenomena of excess estrogen as estrogen dominance . This condition, which is toxic to the body, is fundamental to the problems of menopause and leads to cancer and other very serious problems.