Higher Out-of-Pocket Costs Linked to Lower Semaglutide Adherence in Obesity

Key Clinical Summary:  

• In a cohort of 8914 commercially insured US adults with obesity who initiated semaglutide, nonadherence was high across all out-of-pocket cost levels, ranging from 73.9% to 83.4%.
• Compared with patients paying $0 to $21 per 30-day supply, those paying more than $168 had a 9-percentage-point higher adjusted probability of nonadherence.
• Adherence declined more substantially once out-of-pocket costs exceeded approximately $75 per 30-day supply, highlighting the potential influence of benefit design and cost sharing on sustained use of glucagon-like peptide-1 receptor agonists.

Higher patient cost sharing was associated with lower adherence to semaglutide among commercially insured US adults receiving the medication for obesity, according to a cohort study published in JAMA Health Forum. The findings highlight a potential challenge for managed care organizations as expanded use of glucagon-like peptide-1 (GLP-1) receptor agonists increases attention to both treatment affordability and the long-term adherence needed to realize clinical benefits.

Clinical trials of semaglutide have demonstrated substantial weight loss when adherence exceeds 85%. However, adherence in routine practice is considerably lower, and previous research has identified treatment costs as one potential barrier to continued GLP-1 receptor agonist use.

Researchers evaluated whether differences in patient out-of-pocket spending were associated with adherence among commercially insured adults with obesity.

Adherence Assessed Across Cost-Sharing Levels

The retrospective cohort study used the Merative MarketScan Commercial Claims and Encounters database and included adults with obesity who newly initiated semaglutide for weight loss between June 2021 and December 2022. Patients with type 2 diabetes were excluded, and participants were followed for 1 year.

The analysis included 8914 patients with a mean age of 45.5 years. Women accounted for 82.8% of the cohort.

Out-of-pocket spending, including copayments, coinsurance, and deductibles, was standardized to a 30-day medication supply and divided into 5 groups: $0 to $21, $22 to $43, $44 to $75, $76 to $168, and more than $168.

Researchers measured adherence using proportion of days covered (PDC), with nonadherence defined as a PDC of less than 0.8.

Nonadherence Increased at Higher Costs

Nonadherence was common throughout the study population, ranging from 73.9% among patients in the middle cost group to 83.4% among those with the highest out-of-pocket spending.

After adjustment for patient and insurance characteristics, the predicted probability of nonadherence remained relatively similar across the first 3 cost groups, ranging from 74.7% to 76.6%.

A more pronounced difference emerged once costs exceeded $75 per 30-day supply. Compared with patients paying $0 to $21, the adjusted probability of nonadherence was 3 percentage points higher among those paying $76 to $168, reaching 79.7% (P = .02).

Patients paying more than $168 per 30-day supply had an adjusted nonadherence rate of 85.2%, representing a 9-percentage-point increase relative to the lowest-cost group (P < .001).

PDC followed a similar pattern. Predicted PDC ranged from 0.44 to 0.46 across the first 3 cost groups but decreased to 0.42 among patients paying $76 to $168 and 0.37 among those paying more than $168.

Sensitivity analyses using different adherence thresholds and cost categories produced similar findings.

High-Deductible Plans More Common in Highest-Cost Group

Insurance design differed substantially between patients with the lowest and highest out-of-pocket costs.

Among patients paying more than $168 per 30-day supply, 51.4% were enrolled in consumer-directed or high-deductible health plans, compared with 27.8% of those paying $0 to $21.

The authors noted that higher cost sharing could disproportionately affect patients with fewer financial resources, potentially creating differences in access to the long-term benefits of GLP-1 receptor agonist therapy.

Importantly, the analysis did not establish that higher costs caused poorer adherence. The researchers adjusted for multiple demographic and clinical characteristics, but the claims database lacked information on socioeconomic status and detailed benefit design.

Implications for Managed Care

The findings may be particularly relevant as payers seek to balance growing demand for obesity medications with their substantial pharmacy expenditures.

Although nonadherence was high regardless of cost-sharing level, the apparent threshold above approximately $75 per 30-day supply suggests that benefit design could influence medication-taking behavior even among patients who initiate treatment.

This distinction is important because access to a prescription does not necessarily translate into consistent medication use. If higher copayments, coinsurance, or deductibles contribute to lower adherence, plans may need to consider how cost-sharing strategies affect the ability of members to remain on therapy long enough to achieve and maintain clinical benefits.

The study also highlights differences between public and commercial coverage. The authors noted that recent federal initiatives are expected to reduce costs for some patients covered by public programs, including a planned $50 monthly Medicare copayment for obesity-indicated GLP-1 medications.

Similar reductions are not currently expected across commercial insurance, leaving some commercially insured patients exposed to higher cost-sharing requirements.

The analysis was limited to commercially insured individuals and reflected the relatively early period of semaglutide use for obesity. It also did not include newer medications such as tirzepatide or determine which specific benefit-design mechanisms—such as deductibles, copayments, or coinsurance—were responsible for patients' out-of-pocket spending.

Conclusion

Among commercially insured adults with obesity initiating semaglutide, nonadherence was common and increased as patient out-of-pocket costs rose, with a more pronounced decline in adherence once costs exceeded approximately $75 per 30-day supply. The findings suggest that cost-sharing and benefit-design decisions may be important considerations for managed care organizations seeking to support sustained use and maximize the clinical value of GLP-1 receptor agonist therapy.

Reference

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