ObjectiveTo systematically review the efficacy and safety of dienogest in the treatment of endometriosis. MethodsThe PubMed, Embase, Cochrane Library, CBM, WanFang Data and CNKI databases were electronically searched to collect randomized controlled trials (RCTs) of dienogest for the treatment of endometriosis from inception to February 2024. Two reviewers independently screened literature, extracted data and assessed the risk of bias of the included studies. Meta-analysis was then performed by using RevMan 5.4 software. ResultsA total of 20 RCTs, involving 2 826 patients were included. Meta-analysis showed that compared with gonadotropin-releasing hormone agonist (GnRH-a), dienogest had similar efficacy. Compared with placebo, dienogest was more effective in reducing endometriosis-related pelvic pain. Compared with oral contraceptives, dienogest performed better in relieving endometriosis-related pelvic pain and improving recurrence and pregnancy rates. Compared with other drugs (such as non-steroidal anti-inflammatory drugs, dydrogesterone, etc.), dienogest could gradually reduce the pain. In terms of safety, dienogest could reduce bone density damage and hot flashes in patients with endometriosis compared with those in the control group. ConclusionCurrent evidence shows that dienogest is effective and safely tolerated in the treatment of endometriosis. Due to the limited quantity and quality of the included studies, the above conclusion needs to be verified by more high-quality studies.