Abstract
BACKGROUND: Endometriosis is a chronic condition affecting women of reproductive age and often associated with pain, impaired fertility, and reduced quality of life. Management requires long-term strategies, with medical treatment preferred over repeated surgery. Treatment selection must balance efficacy, cost, patient preference, and safety. Dienogest is a progestin shown to be effective, but real-world data in Thai women remain limited. This study aimed to evaluate the efficacy and safety of dienogest in this population. METHODS: This single-arm, real-world prospective observational study was conducted at King Chulalongkorn Memorial Hospital, Bangkok, Thailand from April 2024 to May 2025. Women with endometriosis received dienogest once daily for 24 weeks. Baseline symptoms, endometriosis-associated pain, and satisfaction were assessed using a visual analog scale (VAS). Follow-up visits were scheduled at 12 and 24 weeks, with reassessment of pain symptoms, satisfaction, and adverse events. RESULTS: A total of 62 participants were included for analysis, with a mean age of 34.2 ± 7.2 years. Dysmenorrhoea was reported by 86.4% and chronic pelvic pain by 60.6% of participants. The mean overall endometriosis associated-pain VAS decreased significantly from 7.5 ± 1.6 at baseline to 2.8 ± 2.2 at 12 weeks and 1.9 ± 1.7 at 24 weeks (p < 0.001). Satisfaction scores were 7.5 ± 1.9 at 12 weeks and 8.1 ± 1.5 at 24 weeks with discontinuation rate of 3 out of 65 women (4.6%). At 12 weeks, common adverse events included acne (29.0%), depressed mood (16.1%), breast pain (14.5%), and headache (14.5%), while weight gain and hot flushes were less common. By 24 weeks, weight gain (26.7%) and acne (26.7%) were most frequently reported. CONCLUSION: Dienogest was associated with reducing pain and good satisfaction in Thai women with endometriosis, with an acceptable safety profile. These findings support its use as a practical long-term management option. TRIAL REGISTRATION: ISRCTN registration approval number ISRCTN68041248 on 13 March 2024.