Osteoarthritis (OA) is a chronic joint disease in which the cartilage that cushions the ends of bones wears down, and the underlying bone, joint lining, and surrounding tissues change along with it. It most often affects the knees, hips, hands, and spine, and typically causes pain with use, stiffness after rest, and reduced range of motion. Excess body weight raises the risk both mechanically, through extra load on weight-bearing joints, and through low-grade inflammation.
Losing weight is one of the most effective treatments for knee OA. In the STEP 9 trial (external link) of adults with obesity and knee osteoarthritis, semaglutide 2.4 mg reduced knee pain and improved physical function more than placebo. Strengthening the muscles around the joint matters too, because weaker muscles leave the joint less supported. See joint pain on a GLP-1 and why strength training matters.