Progestin

A progestin is a synthetic progestogen that has progestational effects similar to progesterone. The two most common uses of progestins are for hormonal contraception (either alone or with an estrogen), and to prevent endometrial hyperplasia from unopposed estrogen in hormone replacement therapy. Progestins are also used to treat secondary amenorrhea, dysfunctional uterine bleeding and endometriosis, and as palliative treatment of endometrial cancer, renal cell carcinoma, breast cancer, and prostate cancer. High-dose megestrol acetate is used to treat anorexia, cachexia, and AIDS-related wasting.

Progesterone (or sometimes the progestin dydrogesterone or 17α-hydroxyprogesterone caproate) is used for luteal support in IVF protocols, questionably for treatment of recurrent pregnancy loss, and for prevention of preterm birth in pregnant women with a history of at least one spontaneous preterm birth. They are also used in judicial chemical castration of sex offenders as well as a treatment options for those suffering from paraphilia.