• Aon researchers found that within two years, improved health outcomes for patients who were taking GLP-1 drugs lowers the growth rate of medical care costs.
• Aon looked at medical claims data for 139,000 U.S.-based workers with employer health coverage who took GLP-1 medications between 2022 and 2024.
• Since 2023, GLP-1s have driven up employer spending on drugs at a faster pace than high-priced specialty drugs used to treat cancer and autoimmune conditions, according to an Evernorth study.

The growing demand for diabetes and weight loss drugs like Mounjaro, Ozempic and Wegovy has helped fuel higher health costs for large employers. For many, the big question is whether the pricey medications known as GLP-1s will pay off by improving worker health and lowering overall health costs over time. Analysts at Aon say it's already happening.  

"We've never seen anything like this, really," said Greg Case, CEO of , an employer benefits services firm. "There was a 44% reduction in major cardiovascular issues. There was substantial reduction in osteoporosis. There was substantial reduction in pneumonia of multiple types."

Aon researchers found that within two years, patients taking GLP-1 drugs saw improved health outcomes, which significantly slowed the growth rate of their medical costs. The rate of growth, known as the medical cost trend – was cut roughly in half, the researchers said.    

GLP-1s come at a list price of more than $1,000 per dose. As broader approval for the drugs spurs higher demand, it's also causing employer drug spending to spike. Since 2023, GLP-1s have pushed costs up at a faster pace than high-priced specialty medications, which include costly cancer and autoimmune treatments, by Evernorth, a division of .

Aon analysts looked at medical claims data for 139,000 U.S.-based workers with employer health coverage who took GLP-1 medications between 2022 and 2024. Beyond the drug costs, the study found GLP-1 patients tend to incur higher medical costs in their first year on the drugs, with more doctor visits to monitor their treatment on the drug and to seek help for other issues such as sleep apnea and esophageal conditions like acid reflux.

"The increase comes about in the first 12 to 15 months," Case said. "They're getting remedies on things that actually are underlying conditions [of obesity]."

But by the end of the second year of treatment with the GLP-1 drugs, the medical cost trend for patients taking them slowed by 7% on average, compared to workers with similar chronic conditions and obesity characteristics who were not taking the drugs, Aon found. For those not taking the drug, the medical cost trend was 14%.

The biggest driver of those savings was the reduction by more than 40% of major adverse cardiac events such as heart attacks and strokes, compared with patients who were not taking the drugs, as well as a reduction in the onset of diabetes. 

Case said with this data, Aon has been able to help clients understand the timeline for seeing a return on providing insurance coverage for GLP-1s for weight loss, in addition to Type 2 diabetes.

"We saw every single place where the cost went down — and it's stunning," said Case. "You can do this in a way that has an ROI, that will literally be an economic return."

Following its research, Aon has launched a subsidized GLP-1 weight management program for its own U.S. workforce, which includes weekly virtual wellness visits and home blood tests to help employees adhere to the drug regimen.

The company will present the full results of its study at the Milken Institute Global Conference on Monday.

Correction: This story has been updated to correct that Aon researchers found GLP-1 use reduces the growth rate of medical costs for employers by 7%. An earlier version misstated the findings.