Endometriosis(EMs)is one of the leading causes of dysmenorrhea,chronic pelvic pain and infertility in women,and the long-term management of EMs should maximize the role of drug therapy.Progestogens are the first-line drugs for the treatment of EMs,among which dienogest has now been taken as the first choice of drug for long-term management of EMs.Dienogest not only effectively relieves EMs-associated pain and prevents postoperative recurrence,but also has been observed to reduced EMs lesion volume to some extent.For young patients with ovarian endometriotic cysts who have not yet given birth,patients with recurrent ovarian endometriotic cysts,and patients with deep-infiltrating endometriosis(DIE)who experience significant pain,dienogest can reduce the volume of lesions,delay or even avoid surgery.In this review,we provide an overview of dienogest's impact on the volume of ovarian EMs and DIE,aiming to provide a basis for individualized nonsurgical treatment of EMs.