Therefore, the synthetic production of Progestin. It can be taken orally without degradation and protect the uterus from unopposed estrogen use. The pharmaceutical companies developed a new drug that could be administered orally with good absorption. It also came with a number of side effects and did not replace the valuable functions of progesterone except to protect the uterus. These side effects included mental depression, weight gain, nausea, insomnia, abnormal vaginal bleeding, breast tenderness, and various skin rashes.
Progestins can also increase a woman's risk of heart disease, liver disease, and lung disease.
It wasn't until the 1970's that is was discovered that progesterone could be absorbed through the skin into the bloodstream. This method of absorption by-passed the liver and was delivered to the tissues unchanged. Although this method of delivery was discovered over 20 years ago, physicians still prescribe progestins with all their side effects and lack of similarity to the much needed hormone, Progesterone. Although 25 mg of progesterone delivered transdermally protects a woman against osteoporosis, it is not clear if this amount will protect her uterus from endometrial carcinoma if she is also on estrogen replacement therapy. If the Progest cream is used with estrogen replacement, I recommend a yearly endometrial biopsy to screen for endometrial cancer.