This observational study aimed to assess the effectiveness and safety of long-term (up to 108 months) treatment with Dienogest in women battling endometriosis-linked chronic pelvic pain.

The study encompassed 157 patients, who took Dienogest 2 mg daily. The enrolled subjects were segregated into two groups based on treatment duration. Group A received short-term therapy (0-15 months) while Group B received long-term therapy (over 15 months). The visual analog scale (VAS) scale was employed to evaluate the impact of the drug on pain levels at baseline (T0) and after 12 (T1), 24 (T2), 36 (T3), 48 (T4), 60 (T5), 72 (T6), and 84 (T7) months.

Ultrasonographic assessment was utilized to measure the dimensions of endometriomas. Additionally, the occurrence of noxious effects and the drug's influence on bone metabolism were examined in Group B through the examination of bone mineral density every 24 months.

Results illustrated a progressive drop in the size of major endometriomas from 33.2 mm to 7 mm after 108 months. Substantial improvements were witnessed in dyschezia, dyspareunia, dysmenorrhea, and non-cyclic pelvic pain (Figure 1).

Menstrual alterations were reported by 22.9% of both groups, while osteopenia was found in 27.6% of long-term therapy patients. Group B also experienced statistically significant higher rates of weight gain, headaches, and libido reduction as opposed to Group A.

In conclusion, long-term therapy with Dienogest adequately controlled endometriosis symptoms, minimized endometrioma size, and demonstrated enhanced positive effects with longer intake, with no serious adverse events reported.