Introduction: This study compares the efficacy of a levonorgestrel-releasing intrauterine system (LNG-IUS) and a low-dose combined oral contraceptive (COC) in reducing adenomyosis-related pain and bleeding.Materials And Methods: A randomized clinical trial included 62 participants complaining of pain and bleeding that was associated with adenomyosis. Participants were randomly assigned to either LNG-IUS or COC treatment.