A new peer-reviewed study published in the Journal of Medical Economics examined whether tirzepatide (the active ingredient in Zepbound and Mounjaro) is worth the cost compared to semaglutide (Wegovy, Ozempic) for people living with obesity — drawing on data from the landmark SURMOUNT-5 head-to-head trial. The findings add a critical financial lens to a debate millions of patients and insurers are already having.
What the Study Looked At
Researchers conducted a cost-effectiveness analysis from the United States societal perspective, comparing tirzepatide at its maximum-tolerated dose (MTD) against semaglutide at its maximum-tolerated dose. Both medications were evaluated as adjuncts to a reduced-calorie diet and increased physical activity — the standard real-world conditions under which these drugs are prescribed.
The study focused specifically on adults with obesity, defined as a body mass index (BMI) of 30 kg/m² or higher, as well as those who are overweight. Importantly, the clinical inputs came directly from the SURMOUNT-5 trial, a Phase 3 head-to-head study that directly compared the two drugs — making this one of the most rigorously grounded cost-effectiveness analyses to date.
Why This Matters for Patients
For the millions of Americans taking or considering GLP-1 and GIP/GLP-1 receptor agonists, cost is often the deciding factor. Both tirzepatide and semaglutide carry high list prices, and insurance coverage remains inconsistent. A societal-perspective cost-effectiveness analysis goes beyond just drug prices — it accounts for broader economic factors like productivity, healthcare utilization, and long-term health outcomes.
Understanding which drug delivers more value per dollar spent can influence formulary decisions by insurers, prior authorization policies, and ultimately which medication a patient is able to access and afford.
Key takeaway: This study used direct head-to-head clinical data from the SURMOUNT-5 Phase 3 trial — not indirect comparisons — to evaluate cost-effectiveness, making it a particularly meaningful reference for payers and patients weighing tirzepatide against semaglutide.
What We Don't Yet Know
The source material for this study does not include the full results or conclusions of the cost-effectiveness analysis, so specific findings — such as which drug was deemed more cost-effective or by what margin — cannot be reported here. The complete data, including incremental cost-effectiveness ratios and modeled outcomes, are available in the full published article in the Journal of Medical Economics.
It's also worth noting that cost-effectiveness analyses represent population-level modeling and may not reflect every individual's clinical situation, insurance plan, or out-of-pocket costs.
What to Watch Next
As more head-to-head data from SURMOUNT-5 and other comparative trials becomes available, expect insurers and pharmacy benefit managers to increasingly cite cost-effectiveness evidence when making coverage decisions. Patients currently on either medication should monitor any changes to their plan's formulary, and those considering starting a GLP-1 or GIP/GLP-1 therapy may find this type of research useful when discussing options with their doctor.
Frequently Asked Questions
Cost-effectiveness data can be a useful tool in conversations about treatment, but it reflects population-level modeling rather than individual circumstances. Talk with your prescriber about which medication is most appropriate for your health profile, coverage situation, and personal goals.
- Peer-reviewed journal article, 'Cost-effectiveness of tirzepatide versus semaglutide for patients with obesity or overweight in the US: evidence from the SURMOUNT-5 head-to-head phase-3 trial,' Journal of Medical Economics, date not specified in source material.