If you’re undergoing fertility treatments, such as in-vitro fertilization, you may have been told that you need progesterone treatments. Many types of medications are introduced into circulation my means of ingestion or injections. However, progesterone is best absorbed via the lining of the vagina—either by suppository, vaginal pill or gel.
Progesterone is often called “the pregnancy hormone.” It is necessary in preparation for implantation of a fertilized egg (embryo) and for the changes that take place in your uterus at the site where the embryo implants itself.
Progesterone is produced by your ovaries during ovulation (the release of a mature egg from an ovary). Specifically, progesterone is produced by cells of the ovarian follicles, which are cysts that contained the eggs prior to ovulation. After 8 weeks of gestation, the placenta makes progesterone.
Progesterone prepares the lining of your uterus (endometrium) for implantation of a fertilized egg. If the fertilized egg does not implant itself into the uterus, your levels of progesterone drop and menstruation begins. If implantation is successful and pregnancy occurs, about 10 weeks into your pregnancy, your placenta takes over and produces high levels of progesterone and continues until your baby is born.