Meds like Ozempic could ease arthritis

Ozempic’s key ingredient may act directly on cartilage to repair creaky joints.

In mice and people, semaglutide can ease symptoms of the joint disease osteoarthritis and thicken the cartilage pillowed between bones, researchers report February 9 in Cell Metabolism.

Thicker cartilage suggests the tissue is being rebuilt, says Di Chen, a physician and biologist at Shenzhen University of Advanced Technology in China. “That’s a good thing,” he says. “That’s the key thing.” More cartilage means more cushion, which means less bone-on-bone grinding and less pain.

Osteoarthritis is the most common form of arthritis, affecting more than 500 million people worldwide. The disease can affect the hands, knees, hips and other joints, causing severe pain as cartilage wears away and tissues inflame. There’s no cure, and no medications that prevent it from becoming worse. Doctors can only help patients try to manage pain, Chen says.

Scientists think weight loss can help alleviate symptoms by reducing the load on joints. That’s why semaglutide, the smash weight loss drug in Ozempic and Wegovy, is considered a contender for osteoarthritis treatment. And indeed, in 2024, a clinical trial in people with obesity reported that the drug  improved joint pain and function. Doctors assumed those benefits were due to weight loss, Chen says. His team wasn’t so sure.

The researchers conducted a similar study in mice with a form of osteoarthritis. One group received semaglutide, the other did not. In the drug-free mice, Chen’s team restricted food intake to match that of the semaglutide group. Both groups shed weight, but only the treated mice saw joint-based benefits. These mice had less pain, less broken-down cartilage and more cartilage growth, the team found. The results suggest that weight loss isn’t driving semaglutide’s benefits.

Chen’s team saw echoes of those results in a small clinical trial in obese people with knee osteoarthritis. After six months on a low dose of semaglutide plus hyaluronic acid, a lubricant made by the body, participants’ knee function improved. This could be due to plumped-up cartilage. MRI exams revealed a 17 percent increase in cartilage thickness in people on semaglutide. That’s compared with a less than 1 percent increase in people on just hyaluronic acid.

Chen’s trial included 20 people; a larger study could help confirm the results. Now, his team wants to puzzle out how semaglutide affects the joints. He has a few hints. Lab experiments suggest the drug scales up energy production in cartilage. That could give the tissue more fuel to heal, Chen says.