Progesterone is a hormone produced by the ovaries that helps maintain a normal menstrual cycle. By preparing the lining of the uterus for implantation by the embryo, Progesterone also plays a critical role in maintaining the early weeks of a pregnancy. At approximately the eighth week of a normal pregnancy, the placenta takes over the role of producing Progesterone for the remainder of the pregnancy. Progesterone helps relax the muscles in the lining of the uterus, and also helps the breasts to develop in preparation for milk production after the birth of a baby.

Some women have ovaries that do not produce adequate Progesterone. These women may experience difficulty in conceiving, or in maintaining a pregnancy once conception occurs. For such women, Progesterone Supplements may be prescribed. When given after ovulation, Progesterone Supplements act on the lining of the uterus to make it thick and nutrient-rich in preparation for implantation of the embryo. Progesterone Supplements may also be prescribed in early pregnancy if a womans blood Progesterone levels are low or if she has a history of repeated miscarriages. Such supplements are typically prescribed for several weeks.

Progesterone Supplements may be taken by mouth, as injections, or as vaginal suppositories. While most oral Progesterone Supplements are capsules, there are some supplements called troches that are placed under the tongue to dissolve. Progesterone injections are usually given in the buttock area, and are reported by some women to be more painful and to cause more soreness than many other types of injections. A Progesterone suppository is inserted into the vagina. It may cause some leaking; this is normal and does not mean that Progesterone is not being absorbed. Progesterone Supplementation may cause some common but transient side effects such as nausea, tiredness and breast tenderness.