40% of Insured Colorado Patients Don’t Fill Their GLP-1 Prescriptions, Study Reveals
A new study published in JAMA Health Forum reveals a striking gap between GLP-1 prescriptions issued and prescriptions filled. Analyzing nearly 10,000 prescription orders across a four-and-a-half-year period, researchers found that 39.9% of insured patients never filled their glucagon-like peptide-1 receptor agonist (GLP-1RA) prescriptions. The findings raise urgent questions about cost barriers, insurance coverage gaps, and equitable access to a drug class that has reshaped the treatment landscape for type 2 diabetes and obesity.
The study drew on data from UCHealth electronic health records and the Colorado All Payer Claims Database. Researchers examined 9,848 GLP-1 prescriptions ordered between January 2018 and September 2022 for 6,094 patients enrolled in Medicare or commercial insurance. Foster Goss, DO, MMSc, FACEP, adjunct professor and site principal investigator at the University of Colorado Anschutz Department of Emergency Medicine, co-authored the research letter. The average patient age in the cohort was 60.9 years.
Overall, 60.1% of patients filled their GLP-1 prescription. Notably, fill rates differed across racial and ethnic groups. Black patients filled prescriptions at a rate of 55.3%, and Hispanic patients at 58.4%, both below the 60.0% rate recorded for white patients. Given that Black and Hispanic populations carry a disproportionately high burden of both diabetes and obesity, these disparities carry significant public health implications.
The clinical indication driving the prescription also influenced fill rates substantially. Patients prescribed a GLP-1 for both diabetes and obesity filled at a rate of 64.6%. Those prescribed for diabetes alone filled at 47.5%, while patients prescribed for obesity alone filled at only 37.2%. Accordingly, out-of-pocket costs are tracked closely with indication. Patients treating obesity alone paid an average of $134.04 for a 30-day supply, compared to $70.32 for those managing both conditions. The study attributes this disparity to less comprehensive insurance coverage for obesity as a standalone indication.
GLP-1 receptor agonists entered the market beginning with Byetta in 2005, followed by Ozempic in 2017 and Mounjaro in 2024 for type 2 diabetes management. Wegovy received approval in 2021 specifically for chronic weight management. Between 2019 and 2023, GLP-1 use for weight management increased by more than 700%. A November 2025 national survey found approximately 12% of U.S. adults currently using a GLP-1 drug for weight loss or a chronic condition. Consequently, access inequities at this scale carry broad population-level consequences.
Goss identifies socioeconomic gradients as central to the fill-rate disparities observed. These include educational attainment, built environment factors, social relationships, and chronic exposure to environmental stressors. Furthermore, the study period concluded in September 2022, before broader adoption of GLP-1 therapy for obesity alone, meaning current disparities may differ in magnitude. The study did not capture cash-pay patients, which represents an additional limitation.
The research concludes that policymakers should examine strategies to improve equitable access to GLP-1 medications. Goss notes that emergency departments frequently serve as safety nets for patients facing access challenges, socioeconomic barriers, and health-related social needs tied to race and ethnicity. This study forms part of a broader NIH-funded research portfolio on prescription drug costs, co-led with Anna Dour Sinaiko, PhD, of the Harvard T.H. Chan School of Public Health, and supported by a National Institute on Minority Health and Health Disparities R01 grant
