These hormones that are produced naturally by our ovaries have a huge significance to our health and shutting off the ovaries can cause or mask serious issues. These two hormones are in a complementary relationship. When one is high the other one is low during the cycle. They are both low at the end and at the beginning of our cycles.
While Estrogen creates, Progesterone maintains. They balance each other’s functions. While getting pregnant is all about Estrogen, keeping the pregnancy is all about Progesterone. They are like yin and yang in our body.
Estrogen causes breasts to grow by increasing breast cell numbers and their multiplication which can be cancerous if the cells keep multiplying, but Progesterone decreases breast cell growth. It is involved in the maturation of breast cells and decreases the rate of multiplication. Estrogen decreases the rate of bone breakdown. Progesterone stimulates bone osteoblasts which are responsible for making new bone to replace old bone. Estrogen increases the production of a protein called thyroid binding globulin. This protein binds the thyroid hormone making it inactive. The body stores fat in order to have enough energy for a fetus if a pregnancy develops, Progesterone increases the activity of the thyroid hormone (by decreasing the thyroid-binding globulin that Estrogen increases) and utilizes the fat stored under Estrogen influence for energy.
Normal Progesterone levels are important for normal body composition. Low Progesterone levels can lead to weight gain. At normal levels, Estrogen prevents depression and insomnia, increases concentration and maintains a normal sex drive. If Estrogen is too high or low, depression, anxiety, insomnia, decreased sex drive and decreased concentration may result. Progesterone stimulates normal sex drive because it can be converted into testosterone which is involved in male and female sex drive.
In the brain, Progesterone binds GABA receptors. These receptors decrease anxiety, insomnia and depression. Progesterone is a natural antidepressant and prevents anxiety. Progesterone decreases uterine muscle contractions which cause menstrual cramps by promoting uterine muscle relaxation and is known as a calming hormone.
Just to compare, Progestin is the artificial Progesterone used in the hormonal birth control. Side effects include blood clots, heart disease, stroke, liver problems, headaches, low sex drive, depression, anxiety, irregular bleeding, problems with blood sugar and hair loss. It is so different from our normal Progesterone.