Dienogest treatment of symptomatic adenomyosis: An in-depth meta-analysis

•Dienogest significantly reduces dysmenorrhea in adenomyosis patients, with a mean reduction in VAS scores of 6 on a 10-point scale.•Greater relief in dysmenorrhea observed in patients with severe baseline dysmenorrhea and longer treatment durations.•Patient response variability and potential adverse effects highlight the necessity for further research on long-term efficacy and individualized treatment strategies. Adenomyosis is a common gynecological disease and a major contributor to dysmenorrhea that substantially reduces the quality of life of the affected. Dienogest has emerged as a promising drug for treating adenomyosis. A few systematic reviews and meta-analyses on this topic have been published recently. However, these meta-analyses were typically based on 2–7 studies, even though numerical data could have been extracted and more studies have been published. Moreover, it is unclear whether there is any characteristic of the patients that is associated with more pronounced improvement after treatment, or which patient subgroup, if any, would benefit most from the dienogest treatment. To evaluate the efficacy of dienogest in alleviating dysmenorrhea associated with adenomyosis and identifying study/patient characteristics that contribute to a better therapeutic response. An in-depth meta-analysis incorporating more recent published studies. An in-depth meta-analysis of 14 studies published up to March 2024, involving 637 patients was conducted, using the visual analog scale (VAS) scores on dysmenorrhea severity as the primary outcome measure. Subgroup analyses and multivariable regression were performed to explore potential factors influencing the treatment effect. Dienogest significantly improved dysmenorrhea, with a mean reduction in VAS scores of 6 on a 10-point scale. Subgroup analyses indicated that dienogest was effective across varying severities of dysmenorrhea and different treatment durations. Notably, patients with higher baseline VAS scores and longer treatment durations experienced greater reductions in VAS scores. Dienogest substantially alleviates dysmenorrhea in women with adenomyosis, particularly among those with severe baseline dysmenorrhea and extended treatment periods. However, variability in patient responses and the potential for adverse effects underscores the importance of individualized treatment strategies. Further large-scale, long-term comparative studies and randomized clinical trials are warranted to optimize treatmen