progestogen

Progestogens are a class of steroid hormones that act on the progesterone receptor. The natural progestogen progesterone is the primary endogenous member of this class, while many synthetic compounds, known as progestins, are used in medicine. Progestogens influence the female reproductive system and other tissues, and receptor activation leads to changes in gene transcription that affect the endometrium, cervical mucus, and myometrium.

Biological role and production: In the menstrual cycle, progesterone rises after ovulation to prepare and maintain the endometrium for potential pregnancy and to support early gestation. During pregnancy, progesterone production shifts from the corpus luteum to the placenta, helping to maintain uterine quiescence and immune tolerance. Progestogens are also produced in smaller amounts by the adrenal glands.

Medical uses: Progestogens are used for contraception (combined estrogen–progestin methods or progestin-only methods), as well as in hormone replacement therapy to protect the endometrium when estrogen is given. They are employed to treat conditions such as dysfunctional uterine bleeding, endometriosis, and luteal phase support in assisted reproduction.

Pharmacology and safety: Synthetic progestins vary in their receptor affinity and additional hormonal activities, including androgenic or antiandrogenic effects. Commonly used progestogens include norethindrone, levonorgestrel, desogestrel, gestodene, drospirenone, and medroxyprogesterone acetate. Side effects can include irregular bleeding, mood changes, weight gain, and breast tenderness; long-term risks, such as venous thromboembolism, depend on the specific progestin and accompanying therapies.

Terminology: The term progestin is often used for synthetic progestogens, while progestogen describes both natural and synthetic hormones acting on the progesterone receptor.