Abstract Study question This review aims to determine the effectiveness of medical preparations in the management of endometrioma size Summary answer Medical treatment from different groups significantly reduces the endometrioma size, and relives painful symptoms What is known already Endometrioma is usually found in more severe stage of endometriosis and likely to be treated surgically. However, surgery of an endometrioma always destroys ovarian tissue and eventually reduces the ovarian reserve. Study design, size, duration Systematic review and analysis.The studies included 810 women in the intervention groups and 442 in the control groups Participants/materials, setting, methods 810 women included in the intervention groups . 442 in the control . All were women with endometrioma; 30-60% had pelvic pain. age was 33.4 years (range 27-39.8). Four electronic databases search PubMed, Embase, CINAHL Google Scholar from each database inception date until 10 .9. 2019 using the specific search term. randomized and nonrandomized were included. trials comparing different medications for endometiotic cyst medical treatment, without language restriction and in consultation with a search methodologist Main results and the role of chance We found 3121studies from the initial search and out of which 3102 were excluded due to they did not fulfil the selection criteria, We included 14 studies for the systematic review leaving 4/14 for the meta-analysis. 14 final studies included for the systematic review out of which 6/14 were uncontrolled. The majority of the studies were prospective (10/14), and four were RCTs. 2/4 (n = 395). controlled studies patient treated with a low-dose (OCP) or NET and dienogest +EE compared with patients treated with placebo, the endometrioma size significantly reduced (odds ratio[OR]1.32;95%CI [0.61,2.84],2studies, 255women, I = 0%).2/4 studies included in meta-analysis patients treated with dienogest versus norethendrone or ethinyl estradiol [EE] plus dienogest (SMD - 6.73;95%CI[-16.53, 3.06],2studies,185 women, I = 83%) Conclusions Medical treatment from different groups significantly reduces the endometrioma size, and relives painful symptoms. Limitations, reasons for caution Despite the nature of the randomized includedstudies, the results of this study are still subjected to confounders relating to clinical and statistical heterogeneity. the studies reported the outcomes differently Wider implications of the findings medical treatment can be given the surgery can be avoided, therefore preserve the ovarian tissue. There is limited controlled study to examine the effectiveness of the treatment for endometrioma. Trial registration number –––––––––