Semaglutide Adherence Falls Once Out-of-Pocket Costs Top $75 a Month

Nonadherence to semaglutide for obesity was high regardless of what patients paid, but worsened significantly once out-of-pocket costs passed roughly $75 per 30-day supply, according to a research letter published in JAMA Health Forum.¹

Nonadherence Was Common Across Every Cost Level

Researchers at the University of Georgia examined 8914 commercially insured adults with obesity who initiated semaglutide for weight loss between June 2021 and December 2022, drawing on the Merative MarketScan Commercial Claims and Encounters database. Patients with type 2 diabetes were excluded. The mean (SD) age was 45.5 (9.4) years, and 7384 patients (82.8%) were women.

Out-of-pocket spending, defined as co-payments, coinsurance, and deductibles standardized to a 30-day supply, was split into quintiles running from $0 to $21 at the low end to more than $168 at the high end. Adherence was measured by proportion of days covered (PDC), with nonadherence defined as a PDC below 0.8.

Unadjusted nonadherence ranged from 73.9% in the middle quintile to 83.4% in the highest. At least 7 in 10 patients missed the adherence threshold no matter what they paid.

Adherence Broke Sharply Above $75 per 30-Day Supply

After adjustment for age, sex, plan type, census region, rural residence, comorbidity burden, quarter of initiation, and other covariates, the association was flat across the bottom 3 quintiles, then dropped off. Predicted nonadherence held between 74.7% (95% CI, 73.0%-76.4%) and 76.6% (95% CI, 74.9%-78.3%) through the third quintile. It rose 3 percentage points in the fourth quintile ($76-$168) to 79.7% (95% CI, 77.8%-81.7%; P = .02), and 9 percentage points in the highest quintile, to 85.2% (95% CI, 83.4%-87.0%; P < .001).

Continuous PDC broke at the same point. Predicted PDC was 0.44 to 0.46 across the bottom 3 quintiles, 0.03 lower in the fourth (0.42; 95% CI, 0.41-0.44; P = .01), and 0.08 lower in the highest (0.37; 95% CI, 0.36-0.39; P < .001). Sensitivity analyses using alternative PDC thresholds and finer cost categorizations produced similar results.

Unadjusted cohort characteristics show where the steepest costs landed. Among patients in the top quintile, 51.4% were enrolled in a consumer-directed or high-deductible health plan compared with 27.8% in the lowest quintile, and 67.5% lived in the South compared with 42.0% in the lowest quintile. They were also somewhat healthier, with 92.2% carrying no comorbidities vs 88.1%.

Because higher cost-sharing may fall hardest on patients with fewer financial resources, the authors wrote, the findings raise concerns about unequal access to the benefits of glucagon-like peptide-1 (GLP-1) receptor agonist therapy.

The Impact on Commercial Plan Design

Public coverage has moved the other way. CMS launched the Medicare GLP-1 Bridge in July 2026, setting a flat $50 monthly co-pay for obesity-indicated GLP-1s, although the demonstration operates outside the Part D benefit and Low-Income Subsidy cost-sharing does not apply.² The study authors cited analysis projecting that commercial plans are unlikely to see comparable reductions, leaving commercially insured patients at cost-sharing levels this analysis links to materially lower adherence.³

Limits on the data bear on that reading.¹ MarketScan captures nothing on race, ethnicity, or socioeconomic status and lacks benefit-design detail granular enough to isolate which cost-sharing mechanism drove out-of-pocket exposure. The study window also reflects early obesity-indication use of semaglutide and excludes newer agents such as tirzepatide.

“Nonetheless, our findings highlight that semaglutide adherence, already low overall, declined further once costs exceeded approximately $75 per 30-day supply,” the authors wrote. “Recent federal agreements seek to lower GLP-1 prices for public programs and uninsured patients, and new Centers for Medicare & Medicaid Services demonstrations will introduce a $50-monthly Medicare copayment for obesity-indicated GLP-1 medications. Commercial plans are not expected to see similar reductions, suggesting that commercially insured patients may continue to face cost-sharing levels that could limit adherence and associated health benefits.”

References

1. Shin E, Kim H, Lee J, Hall DB, Rajbhandari J. Out-of-pocket costs and adherence to semaglutide for obesity among commercially insured adults. JAMA Health Forum. 2026;7(8):e263113. doi:10.1001/jamahealthforum.2026.3113

2. Shaw M. Medicare GLP-1 Bridge launches, but who actually qualifies? AJMC^®. July 6, 2026. Accessed September 22, 2026. https://www.ajmc.com/view/medicare-glp-1-bridge-launches-but-who-actually-qualifies-

3. Dusetzina SB, Sachs RE. Insurance coverage and pricing of weight-loss drugs in the United States. N Engl J Med. 2026;394(2):105-107. doi:10.1056/NEJMp2516280