OBJECTIVE: To assess the extent of off-label glucagon-like peptide-1 receptor agonist (GLP-1) prescribing among individuals without diabetes in Medicare Part D.
STUDY SETTING AND DESIGN: This cross-sectional study included Medicare Part D beneficiaries who initiated GLP-1s. We used a difference-in-differences event-study design with insulin initiators as a control group to interpret time trends in prescribing without diabetes evidence.
DATA SOURCES AND ANALYTIC SAMPLE: We identified beneficiaries initiating semaglutide or tirzepatide between 2019 and 2023 using a 20% sample of Part D event data. Nondiabetic use was defined as the absence of a diabetes diagnosis or a prescription history of diabetes medications within 1 year before or after 6 months of the first GLP-1 fill.
PRINCIPAL FINDINGS: Among 126,263 new GLP-1 users, 9.0% were prescribed without diabetes, rising to 13.8% in 2023. This practice was more common among younger, female beneficiaries with obesity. From 2021 to 2023, the share of initiators without diabetes evidence increased by 13.3 percentage points (95% CI, 12.9-13.6), beyond changes observed among insulin initiators.
CONCLUSIONS: This growth underscores the substantial budgetary implications for Medicare, particularly amid ongoing policy discussions around expanding coverage of GLP-1s for weight management.
