Clinical and Experimental Obstetrics & Gynecology (CEOG) is published by IMR Press from Volume 47 Issue 1 (2020). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement with S.O.G.
Purpose of Investigation: Dienogest is marketed in Japan as the first time in the world for novel treatment of endometriosis. This paper details the retrospective investigation how effective long-term use of dienogest is for the treatment of endometriosis. Materials and Methods: Data on 21 patients of diagnosed as endometriosis/adenomyosis and treated with dienogest for more than 12 months (ten patients with 60-month period) were collected. Results: Dienogest was effective in reducing pain and size of ovarian endometrioma, while the size of adenomyosis remained the same size as before treatment. The most frequent adverse effects were irregular bleeding. There was no reduction in bone mineral density after 60 months while plasma estradiol was maintained at a slightly lower level. Clinical parameters for did not change during a 60-month period. Conclusions: These results show that dienogest is safe to use for at least five years and is an effective treatment for endometriosis for long periods.