Tirzepatide shows higher one-year persistence than semaglutide in military cohort

Among 10,649 active-duty service members who began a GLP-1 medication for weight management, one-year persistence was 81.9% on tirzepatide (Zepbound), 70.7% on semaglutide (Wegovy) and 34.2% on liraglutide (Saxenda), according to a retrospective cohort study of the Military Health System ^[1].

The study followed service members who started one of the three drugs between January 1, 2021 and December 31, 2025 ^[1]. Persistence was defined as the time until a first gap in therapy longer than 90 days. The researchers used Kaplan-Meier survival analysis to estimate persistence rates and a multivariable Cox proportional hazards model to identify predictors of discontinuation ^[1].

Adherence, measured as the proportion of days covered, followed the same order: 78.2% for Zepbound, 71.6% for Wegovy and 48.7% for Saxenda ^[1]. The difference in persistence across the three drugs was statistically significant (log-rank P < .001) ^[1].

After adjustment for other factors, the hazard of discontinuation was 33% lower for Zepbound than for Wegovy (hazard ratio 0.67, 95% confidence interval 0.61-0.74) ^[1]. For Saxenda, the study reported a 26% higher hazard than Wegovy (hazard ratio 1.26, 95% confidence interval 1.01-1.16); as published, that interval does not include the reported hazard ratio ^[1]. Male service members had a higher hazard of stopping than female service members (hazard ratio 1.12, 95% confidence interval 1.02-1.22) ^[1].

The published findings do not say why patients stopped. Reasons such as side effects, supply problems or patient preference were not reported ^[1].

Why it matters for patients

Persistence is the practical question behind weight management: these medicines are generally used long term, and this study measured whether people kept filling prescriptions, not how much weight they lost. In this cohort, roughly one in five patients on tirzepatide and about three in ten on semaglutide had a gap in therapy longer than 90 days within the first year; about two-thirds of those on liraglutide did ^[1].

The setting is a major caveat. All 10,649 patients were active-duty service members, and their coverage through the Military Health System does not depend on prior authorization or out-of-pocket cost the way most US patients' coverage does ^[1]. Because coverage in this group was guaranteed, the persistence rates reported here may be higher than those seen among commercially insured or Medicaid patients, who often face cost and approval barriers. Whether those patterns hold elsewhere has not been established ^[1].

A second limitation is that the study compared three drugs that differ in active ingredient and in how often they are taken, but it did not test whether those differences explain the persistence results ^[1]. The authors say their findings have implications for clinical decision-making and formulary management aimed at improving long-term outcomes ^[1].

What happens next

The findings are published in the journal Military Medicine ^[1]. It has not been reported whether the researchers plan longer follow-up of this cohort or an analysis of the specific reasons patients discontinued therapy ^[1]. No information on cost, weight-loss outcomes or side-effect rates for this cohort appears in the published findings, and the authors did not report whether the differences between tirzepatide and semaglutide reflect tolerability, dosing or other factors ^[1].