Progesterone is a hormone produced in the ovaries and adrenal glands that plays a role in a number of processes in the body. Progesterone helps to regulate a woman's menstrual cycle and supports pregnancy, helps regulate mood and performs a range of other functions. The concentrations of progesterone in the body become carefully regulated, and too much or too little circulating progesterone can lead to a number of effects. Excess progesterone causes a number of deleterious effects, some of which can be life threatening.
Low Sex Drive
Excess progesterone levels may cause low libido, especially in men. Sex drive is regulated by relative levels of sex hormones. In general, higher testosterone is linked to a high sex drive, whole excess estrogen or progesterone may lead to a low sex drive. Testosterone is synthesized from a precursor molecule, and converting the precursor to testosterone requires a number of steps. Progesterone inhibits the synthesis of testosterone by inhibiting one of these steps, reports BHRT-Resource.com. Without proper testosterone synthesis, overall testosterone levels decrease, and sex drive drops. Therefore, sustained levels of excess progesterone can lead to a sustained low sex drive.
Risk of Breast Cancer
Another possible effect of excess progesterone is the development of breast cancer. Cells within the breast are hormonally responsive, so excess progesterone has an effect on breast tissue. Specifically, progesterone induces breast inflammation, which may contribute to breast cancer. Inflammation induces the growth of blood vessels, an essential step in tumor progression required to nourish tumor growth. Michigan State University indicates that excess progesterone as a result of hormone therapy in post-menopausal women activates cancerous inflammatory pathways in breast tissue. Women with a high risk of breast cancer should take care to monitor progesterone levels to reduce the risk of developing cancer.
Blood Clots
Exposure to excess progesterone, such as progesterone in some hormone therapies, can increase the risk of developing blood clots, reports the BloodPressure website. A blood clot can form anywhere within the blood vessels of the body and cause serious side effects. If the clot blocks blood flow to tissues, the affected tissues will eventually die. Blood clots can also travel in the bloodstream to the heart or lungs and cause other serious effects. Women with a medical history of developing blood clots should consider abstaining from hormone therapy, since progesterone can worsen existing clotting conditions.
