How to use Prometrium. Read the Patient Information Leaflet provided by your pharmacist before you start using this drug and each time you get a refill. What is progesterone (First Progesterone MC10, Menopause Formula Progesterone, Prometrium)? Progesterone is a female hormone important for the regulation of ovulation and menstruation. Progesterone is used to cause menstrual periods in women who have not yet reached menopause but are not having periods due to a lack of progesterone in the body. PROMETRIUM Capsules should not be used in patients with known hypersensitivity to its ingredients. PROMETRIUM Capsules contain peanut oil and should never be used by patients allergic to peanuts. PROMETRIUM Capsules contain peanut oil and should never be used by patients allergic to peanuts. Prometrium is a female hormone important for the regulation of ovulation and menstruation. Prometrium is used to cause menstrual periods in women who have not yet reached menopause but are not having periods due to a lack of progesterone in the body. Progesterone (P4) is a medication and naturally occurring steroid hormone. It is a progestogen and is used in combination with estrogens mainly in hormone therapy for menopausal symptoms and low sex hormone levels in women. Prometrium: Progesterone belongs to the class of medications called progestins. It is used in combination with postmenopausal estrogen replacement therapy (ERT) to prevent the estrogen from thickening the lining of the uterus (a condition known as endometrial hyperplasia). This significantly reduces the risk of endometrial cancer. This. PROGESTERONE is a female hormone. This medicine is used to prevent the overgrowth of the lining of the uterus in women who are taking estrogens for the symptoms of menopause. Warning Do not use estrogens with a progestogen like Prometrium (progesterone capsules) to prevent heart disease or dementia. Using estrogens with a progestogen may raise the chances of having a heart attack, a stroke, breast cancer, a blood clot, or dementia.