Military Health System cohort reports 82% one-year persistence on tirzepatide

A retrospective study of active-duty service members found that people who started tirzepatide (Zepbound) stayed on the drug longer over one year than those who started semaglutide (Wegovy) or liraglutide (Saxenda) ^[1]. The findings come from the Military Health System and cover 10,649 active-duty members who began one of the three GLP-1 receptor agonist medications between January 1, 2021, and December 31, 2025 ^[1].

Researchers tracked persistence, defined as the time until a patient had a gap in therapy longer than 90 days ^[1]. One-year persistence was 81.9% for Zepbound, 70.7% for Wegovy, and 34.2% for Saxenda, a difference the study authors called statistically significant ^[1]. Average yearly adherence, measured as the proportion of days covered by medication, followed the same pattern: 78.2% for Zepbound, 71.6% for Wegovy, and 48.7% for Saxenda ^[1].

After adjusting for other factors, the study's Cox proportional hazards model found the risk of stopping treatment was 33% lower for Zepbound than for Wegovy (hazard ratio 0.67, 95% confidence interval 0.61 to 0.74) ^[1]. The risk of stopping was 26% higher for Saxenda than for Wegovy (hazard ratio 1.26, 95% confidence interval 1.01 to 1.16, as reported by the study) ^[1]. The study also found that male service members had a 12% higher hazard of discontinuation than female service members (hazard ratio 1.12, 95% confidence interval 1.02 to 1.22) ^[1].

The study authors concluded that Zepbound and Wegovy were linked to substantially higher persistence and adherence than Saxenda in this group of active-duty personnel, and said the results could inform decisions about which drugs health systems stock and cover ^[1].

Why it matters for patients

Staying on a GLP-1 medication for a full year, without a gap longer than 90 days, is one measure of whether people tolerate a drug well enough and find it convenient enough to keep taking it. This study suggests that among active-duty troops, people who started on tirzepatide were more likely to still be filling prescriptions a year later than those who started on semaglutide, and both were far more likely to continue than those on liraglutide ^[1].

But this is a specific population. Active-duty service members typically do not face the same out-of-pocket costs, insurance denials, or prior-authorization hurdles that many civilian patients run into when trying to get or keep a GLP-1 prescription. The study itself frames the comparison as being among service members within the Military Health System, not the general public ^[1]. That means the persistence rates reported here may reflect how well people tolerate these drugs when cost and access are not major obstacles, rather than how persistence looks for someone paying cash or navigating a commercial insurance plan's coverage rules.

The study does not report why people stopped taking their medication, whether due to side effects, insufficient weight loss, deployment schedules, or other reasons. It also does not report weight-loss outcomes tied to persistence, so it does not show whether staying on treatment longer translated into greater weight loss in this cohort.

What happens next

The study covers prescriptions started through the end of 2025, and it was published as a peer-reviewed cohort analysis ^[1]. It is not yet known whether similar persistence patterns would appear in civilian populations with different insurance coverage, cost-sharing, or drug shortages, or whether newer therapies not included in this study, such as orforglipron (Foundayo), would show comparable persistence.