OBJECTIVES: Lorcaserin is a serotonin 2C receptor agonist approved in the U.S. as an adjunct to a reduced-calorie diet and increased physical activity for chronic weight management in adults with an initial Body Mass Index (BMI) ≥ 30 or ≥ 27 with at least one weight-related comorbid condition. There is limited information regarding the real-world use of lorcaserin. METHODS: A retrospective data analysis was performed using Humedica Electronic Health Record. Patients who were ≥ 18 years old, had at least two written prescriptions of lorcaserin, and had records of medical activities during 6 months pre- and post- index date (defined as the first written lorcaserin prescription date) were identified. All patients were required to have weight values at baseline, week 12, and week 24. Patients’ weight changes from baseline were observed at week 12 and week 24. Patients with weight loss of ≥5% at week 12 were defined as W12 responders. RESULTS: A total of 490 patients were identified. The average percent weight loss at week 12 was 2.1±4.1%. The W12 responders were 21% of patients (n=105) with an average weight loss of 7.6±2.3%.  At week 24, the W12 responders lost an average of 9.2±4.9% of baseline weight. CONCLUSIONS: Real world data demonstrated that lorcaserin W12 responders experienced significant weight loss at week 24, comparable with clinical trial results. There were fewer responders in this real world analysis compared to clinical trials, which may be due, at least in part, to unavailability of prescription fill, adherence to medication, and/or behavior modification verification in this dataset.