How Does Ozempic Work?

News around drugs like Ozempic moves fast: There’s a steady drumbeat of new studies, new regulatory approvals, new shortages, new insurance hurdles. Here’s a primer on Ozempic and other popular drugs being widely used for diabetes and weight loss.

How do drugs like Ozempic work?

Ozempic belongs to a class of medications called GLP-1 receptor agonists, named after a hormone in the human body that they are designed to imitate.

In 2017, the Food and Drug Administration approved Ozempic to treat Type 2 diabetes, but people have also used the drug off-label to lose weight. In the last few years, other similar drugs have hit the market: Wegovy, a drug approved for weight loss and to reduce the risk of cardiovascular issues in some adults; Mounjaro, approved for Type 2 diabetes; and Zepbound, authorized for weight loss. These medications are all weekly shots.

Both Wegovy and Ozempic contain semaglutide, which mimics the hormone GLP-1 to stimulate insulin production in the pancreas and slow down stomach emptying, making people feel fuller faster, and for longer. Mounjaro and Zepbound work similarly, but they use tirzepatide (rather than semaglutide) to simulate both GLP-1 and a second hormone, GIP.

Crucially, semaglutide and tirzepatide also target the brain: They curb hunger signals, silencing what many users have called “food noise.”

The drugs don’t work for everyone. In clinical trials, a small fraction of participants have not lost significant weight or seen meaningful improvements in blood sugar control. “We haven’t quite figured out yet who will respond well,” said Dr. Scott Hagan, an assistant professor of medicine at the University of Washington who studies obesity.