Progesterone is used as a medication. It is used in combination with estrogens mainly in hormone therapy for menopausal symptoms and low sex hormone levels in women. It may also be used alone to treat menopausal symptoms. Studies have shown that transdermal progesterone (skin patch) and oral micronized progesterone are effective treatments for certain symptoms of menopause such as hot flashes and night sweats, which are otherwise referred to as vasomotor symptoms or VMS.
It is also used in women to support pregnancy and fertility and to treat gynecological disorders. Progesterone has been shown to  prevent miscarriage in women with 1) vaginal bleeding early in their current pregnancy and 2) a previous history of miscarriage. Progesterone can be taken by mouth, through the vagina, and by injection into muscle or fat, among other routes.