Elagolix is a GnRH receptor antagonist, approved for treatment of endometriosis-associated pain at 150mg QD or 200mg BID, in the US, Canada, and Israel. This study examined the real-world impact of elagolix on woman’s health-related quality of life and treatment tolerability, as self-reported by women with endometriosis. This was a 6-month (M) interim analysis of the LOTUS study, an ongoing 24M observational study, collecting data via monthly electronic surveys administered through a patient support program, utilized by women in the US. Patients were pre-menopausal women, 18-49yrs. Analysis focused on women who confirmed they were taking elagolix (150mg QD or 200mg BID) every month until evaluation at 3M or 6M. Significance of the mean change from baseline for each of 6 domains of the Endometriosis Health Profile-30 questionnaire (EHP-30) at 3M (n=70) and 6M (n=44) was determined using paired t-tests. Responders for each domain were determined using published thresholds for a clinically meaningful response1. Treatment tolerability satisfaction was determined through the Endometriosis Treatment Satisfaction Questionnaire (ETSQ) and descriptive analysis was included. EHP-30 scores were statistically significantly reduced (i.e., improvement in EHP-30 domains) from baseline to 3M and 6M, respectively, for all 6 domains (See Table 1). Women with baseline moderate to severe (NRS≥4) dysmenorrhea, NMPP, or dyspareunia and completed the ESTQ (n=42, 36 and 26, respectively) responded “Somewhat Satisfied”, “Satisfied”, or “Extremely Satisfied” with 6M tolerability (lack of bothersome side effects) at 64.3%, 61.1%, and 42.3%, respectively. This real-world, patient-reported data demonstrates that elagolix had a positive impact on women’s quality of life at 3M and 6M, aligning with the results reported in elagolix phase 3 clinical trials2.