Progestin effects in endometriosis treatment: new research on mechanisms

New research on mechanisms of progestin effects in endometriosis treatment has been performed with dienogest (DNG), which has recently been launched in this regard. It is effective in the same low dosage of 2 mg/day, similar to the use of contraception and hormone therapy, whereas other progestogens (with the exception of dydrogesterone) must be given in much higher dosages to treat typical symptoms of endometriosis. This short review summarizes experimental studies on DNG. They demonstrate strong antiproliferative effects in endometrial and endometriotic cells or experimental endometriosis, as well as anti-inflammatory and antiangiogenic actions. By direct action on the ovarian folliculogenesis DNG lead to only modest suppression of estradiol production in contrast to the high-dosed progestogens or to gonadotropin releasing hormone (GnRH) agonists. These effects add to the well-known tolerability because DNG is very neutral regarding cardiovascular, metabolic or central action which also makes it suitable for long-term therapy.