A recent study by researchers at the University of Chicago shows that some new medications for obesity—especially tirzepatide and semaglutide—can lead to major health improvements, such as fewer cases of obesity, diabetes, and heart disease.
However, these benefits come at a high price, and the medications may not be affordable or cost-effective for many people at their current prices.
The study, published in JAMA Health Forum, looked at the long-term health impact and cost-effectiveness of four weight-loss medications: tirzepatide, semaglutide, phentermine-topiramate, and naltrexone-bupropion.
These were compared to lifestyle changes alone, such as better diet and more exercise.
Obesity affects over 40% of adults in the U.S. and is linked to serious health issues, including heart problems, diabetes, and high medical costs. Medications like semaglutide and tirzepatide—both known as GLP-1 receptor agonists—have been shown to help people lose weight and improve heart and metabolic health.
But because of high demand and limited supply, these drugs are expensive and not always covered by insurance.
To understand the full picture, researchers used real-world data from the National Health and Nutrition Examination Survey (NHANES) and applied a detailed simulation model called DOC-M.
This model allowed them to predict how each treatment option would affect a person’s health over their lifetime. The analysis included over 4,800 people, representing about 126 million U.S. adults who would qualify for obesity treatment based on their weight and health conditions.
Each simulation considered a combination of lifestyle changes and one of the four medications. The team estimated how much weight people might lose, how their risks of diabetes and heart disease might change, and how likely they were to stop taking the medication.
They also included the cost of the drugs, other medical expenses, and losses related to health problems, using 2023 U.S. dollars.
Key Results:
- Tirzepatide prevented the most health problems: about 46,000 fewer obesity cases, 21,000 fewer diabetes cases, and 11,000 fewer heart disease cases per 100,000 people.
- Semaglutide also performed well, preventing over 32,000 obesity cases, 19,000 diabetes cases, and 8,000 heart disease cases per 100,000.
- People who took tirzepatide gained the most life-years (0.50) and quality-adjusted life-years (QALYs) (0.35), followed by semaglutide (0.35 life-years and 0.25 QALYs).
However, cost-effectiveness is where things became more complicated.
- Naltrexone-bupropion was the most affordable and had an 89% chance of being cost-effective. It was also the only treatment that actually saved money.
- Phentermine-topiramate was moderately cost-effective, with a 24% chance of meeting the accepted cost-effectiveness benchmark of $100,000 per QALY.
- Tirzepatide and semaglutide, despite their strong health benefits, were not considered cost-effective at current prices. Tirzepatide had a cost-effectiveness ratio of about $197,000 per QALY, and semaglutide’s was even higher, at $468,000 per QALY.
The study estimated that prices would need to drop by over 30% for tirzepatide and nearly 82% for semaglutide to become cost-effective under widely accepted standards.
The analysis also showed that these medications are most valuable for people who already have other health conditions, like diabetes or heart disease, where the potential health gains are larger. Still, even for high-risk patients, the cost remains a major issue.
This study provides a clear message: powerful new obesity drugs like tirzepatide and semaglutide can make a big difference in people’s health—but they’re currently too expensive to be widely used in a cost-effective way.
While these drugs help prevent serious diseases and improve life expectancy, their high cost puts them out of reach for many people and strains health care budgets.
From a public health perspective, the study highlights the need to lower prices or find other affordable weight-loss strategies. That could include more use of older, cheaper medications like naltrexone-bupropion, or better support for long-term lifestyle changes, such as healthy eating and exercise programs.
For patients and doctors, the findings suggest that while these newer medications are very effective, decisions about using them should also consider affordability and insurance coverage.
As demand for antiobesity medications continues to grow, this study adds to the conversation about how to balance innovation, access, and cost in the fight against obesity.
If you care about weight loss, please read studies that hop extract could reduce belly fat in overweight people, and early time-restricted eating could help lose weight .
For more health information, please see recent studies about a simple path to weight loss, and results showing a non-invasive treatment for obesity and diabetes.
The research findings can be found in JAMA Health Forum.
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