Live Geos: https://partners.subjectwell.com/publishers/geos_report/9fd29179-bfe6-4d72-a112-eb35b1e43062 Endometriosis Patient Profile Gender: Female Ages: 18-49 Compensation: Compensation for time and travel Study Description: The purpose of this clinical study is to test the safety and effectiveness of a medication when taken alongside a combination hormonal birth control pill in premenopausal women with endometriosis. While this medication has been FDA approved for the treatment of endometriosis related pain, its effectiveness when combined with the oral contraceptive is investigational (experimental) for the purposes of this study. You will be required to stop taking any prescribed birth control for the duration of the study and use at least 2 forms of non-hormonal birth control. Screening for this study will last up to approximately 4 months. If you qualify and are enrolled into the study, screening will be followed by a 3-month period where you will receive both the combination hormonal birth control pill and the study medication or their matching placebos. This is followed by a 15-month open label period where participants are guaranteed to receive active study medication (no placebos). The total study treatment period will last up to 18 months. You will be asked to attend regular study visits and complete up to 10 phone calls with the study site. During these visits, you will complete various diagnostic and laboratory tests. The doctor’s office conducting the study will be able to provide you with more information about the study requirements. No health insurance is required. Participants who qualify for the study will receive trial-related procedures and study medication at no cost and will be compensated for time and travel. Diagnosis: Endometriosis is a disorder where similar tissues inside the uterus start to grow outside the uterine cavity. This lining of the uterus is called endometrium. Its symptoms vary from woman to woman. The severity of pain cannot indicate the endometriosis stage. Qualifications: - Must be diagnosed with Endometriosis through a surgical procedure such as a laparoscopy or laparotomy - Cannot have had a hysterectomy or had both ovaries removed - Cannot be breastfeeding, pregnant, or actively trying to become pregnant - Cannot be a current or former nicotine user over the page of 33