What you need to know about side effects of GLP-1 drugs
A class action lawsuit has been filed over alleged side effects of GLP-1 drugs such as Ozempic, Wigovy, and Munjaro.
Americans’ voracious appetite for GLP-1 weight loss drugs has put the United States on pace to spend more than $1 trillion on prescription drugs this year, a new report says.
Spending on prescription drugs in the United States is expected to increase nearly 13% to $915 billion in 2025 and exceed $1 trillion by 2026, according to a report from the American Society of Health-System Pharmacists (ASHP) released April 30.
A key reason for such growth in drug sales is the popularity of the weight loss and diabetes drugs tirzepatide and semaglutide.
Eli Lilly’s tirzepatide, sold as Zepbound for weight loss and Munjaro for the treatment of type 2 diabetes, is the best-selling drug in the United States. According to the ASHP report, nearly $63 billion in wholesale purchases were generated in 2025.
Novo Nordisk’s semaglutide, sold as Wigovy for weight loss and Ozempic for treating type 2 diabetes, ranked second last year with more than $59 billion. According to the ASHP report, sales of Eliquis, the No. 3 blood thinner, reached $29 billion, less than half of the amount spent on each weight-loss drug.
The association analyzed figures from a national database that tracks wholesalers’ purchases from drug companies. The wholesaler then sells the drugs to hospitals, clinics, retail and postal service pharmacies, home health agencies, long-term care facilities, and other healthcare facilities.
The amount consumers pay for prescription drugs varies based on rebates, discounts, and insurance coverage.
Consumers pay less. Pharmaceutical companies raise more money
Sales of weight-loss drugs Zepbound and Wegoby continued to accelerate even as Lilly and Novo lowered prices to attract more cash-paying customers. Research shows that nearly half of employment insurance plans cover anti-obesity drugs. Novo and Lilly have appealed to uninsured consumers by selling their drugs directly through their respective pharmacies and telemedicine providers.
“They’re a phenomenon,” said Eric Tichy, lead author of the ASHP report and director of supply chain management at the Mayo Clinic, about public demand for GLP-1 drugs. “What happens when you collide with the obesity epidemic in the United States from a weight loss perspective.”
On April 30, Eli Lilly reported impressive quarterly sales and profit growth driven by sales of Zepbound and Mounjaro. The first-quarter results came despite Lilly lowering the price of Zepbound for U.S. consumers who buy the drug directly from Lilly pharmacies. Lilly launched its weight-loss drug Foundayo in April and expects the drug to boost sales this year.
Spending on popular GLP-1 drugs is expected to accelerate this year with the launch of weight loss drugs (Novo’s Wigovy and Lilly’s Foundayo).
Both Lilly and Novo Nordisk are betting that their daily weight-loss drugs will become a popular option for consumers who want to avoid injections or who have been reluctant to take weight-loss drugs.
Lilly CEO David Rix told analysts that lower prices on the popular weight-loss drug helped boost sales.
“Every time we lower the price, we see pretty significant expansion,” Ricks said.
Lily’s Ricks said lower prices are attracting cash-paying customers, but it’s important to expand insurance coverage for anti-obesity drugs.
Earlier this month, Medicare announced a bridge program that will begin covering GLP-1 weight loss drugs from July 1 to December 31, 2027. Under this program, people on Medicare would pay a $50 monthly copayment to obtain the drug.
Patients use more prescription drugs, increasing costs
ASHP’s report predicts that U.S. spending on prescription drugs will increase 10 to 12 percent this year to more than $1 trillion.
Increased sales of GLP-1 drugs, combined with increased usage by consumers and patients, are increasing overall pharmaceutical spending. Only about 1% of total drug spending can be attributed to drug price increases, the report said.
Still, other reports indicate that drug price increases are common. As of Jan. 9, companies had raised list prices for more than 850 drugs by a median of 4% compared to 2025, according to data from 46Brooklyn Research, a drug pricing nonprofit. However, some widely used drugs, such as Eliquis and Jardiance, have had their prices reduced by 43% and 44%, respectively, 46 Brooklyn reported.
In 2025, cancer drugs accounted for the largest and fastest-growing category of pharmaceutical spending in clinics and hospitals. Pembrolizumab, sold under the brand name Keytruda, was the top-selling oncology drug in both clinics and hospitals, according to the ASHP report.
One factor driving increased prescription drug use could be changes in Medicare coverage policies, Tichy said.
Medicare has set a $2,100 cap on out-of-pocket drug costs for older Americans in 2026 under Medicare Part D, which covers pharmacy and mail-order prescriptions. The cap is part of the Inflation Control Act, the 2022 federal climate and healthcare bill that also gave Medicare the power to negotiate drug prices with drug companies.
“The use of more expensive drugs may be increasing because they are less costly to patients,” Tichy said.
