2.2. Participants
endometriosis
ENDOMETRIOSIS, SECONDARY
This study enrolled healthy women who met the following criteria: (1) aged 25–40 years, (2) had a menstrual cycle of 25–38 days with a menstrual period lasting 3–7 days, and (3) experienced menstrual-related symptoms before and during menstruation. Participants with menstrual-related symptoms were defined in this study as having a total score of 1 or higher on the menstrual distress questionnaire (MDQ) [The effect size of OLL2809 in this study was predicted to be 0.7 based on a previous study involving patients with endometriosis [The primary screening included blood and urine sampling, anthropometric measurements, a lifestyle questionnaire, J-CMI, SCL-KM, MDQ, and medical interviews with participants who provided consent. From the participants meeting the inclusion criteria and not meeting the exclusion criteria, 120 participants with higher MDQ total scores (combined physical and psychological symptom scores) in the primary screening were selected. Furthermore, as the secondary screening, 80 participants with MDQ total scores close to the median at baseline were selected. Menstrual symptoms are known to vary significantly among individuals [