Objective: To investigate the effect of low doses of vaginal gestrinone with oral Pinus pinaster extract and resveratrol on endometriosis-related pain in patients with deep endometriosis using Mirena® and still experiencing symptoms during use of this levonorgestrel-releasing intrauterine system. Patient and methods:This was an open observational study conducted with 20 patients with deep endometriosis and severe pain to investigate the clinical effectiveness of low doses of vaginal gestrinone to improve pain and induce amenorrhea in patients not responding adequately to Mirena®. In Group A (n=14), treatment with vaginal gestrinone, oral Pinus pinaster extract and resveratrol began 3-6 months after Mirena® insertion when it was found that these patients were not responding satisfactorily to treatment. In Group B (n=6), patients initiated treatment with vaginal gestrinone, oral Pinus pinaster extract and resveratrol at the time of Mirena® insertion. The effect of gestrinone on aromatase expression in the eutopic endometrium was also investigated by immunohistochemistry in all patients.