Experts Discuss Whether This Weight Loss Drug Can Relieve Knee Pain

Semaglutide, sold under the popular brand names Ozempic and Wegovy, is prescribed mainly for managing weight loss and type 2 diabetes. But the medication may also help reduce knee pain in obese people with osteoarthritis, according to a recent study.

The trial results published in the New England Journal of Medicine found people with osteoarthritis who took semaglutide and also followed a healthy diet and exercise regimen had less knee pain than those who only used diet and exercise to lose weight. The trial was funded by Novo Nordisk, the company that makes semaglutide.

“There is a significant need for non-surgical and sustainable treatment options for those living with obesity-related osteoarthritis,” lead study author Henning Bliddal, MD, a professor of rheumatology and director of the Parker Institute at Copenhagen University Hospital, said in a press release. The “trial aimed to provide rigorous evidence as to how semaglutide may help these people.”

Osteoarthritis is a common joint condition where the protective cartilage that cushions the ends of bones wears down over time, causing inflammation and leading to pain, stiffness, and reduced mobility. About 528 million people worldwide have osteoarthritis, with the knee being the most commonly affected joint, according to the World Health Organization.

The clinical trial included around 400 patients with knee osteoarthritis who were also overweight. All of the patients had a body mass index (BMI) of 30 or more, which is the threshold for obesity, and about 40% had BMIs over 40, indicating severe obesity.

The average age of the participants was 56, and about 80% were women, who are more prone to developing osteoarthritis than men. Participants received either weekly injections of semaglutide or a placebo for 68 weeks, along with guidance on healthy eating and exercise.

At the end of the trial, participants who received semaglutide lost an average of about 14% of their body weight, or around 33 pounds, while those in the placebo group lost 3%, or roughly 7 pounds. In addition, knee pain scores for those on semaglutide decreased by about 42 points on a 100-point scale, while participants in the placebo group experienced a reduction of 28 points.

The study suggests that semaglutide may help reduce knee pain, but the research didn’t establish whether the drug improves pain independently of weight loss, said Mir Ali, MD, a board-certified general surgeon, bariatric surgeon, and medical director of MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center in Fountain Valley, California. 'The patients with the most improvement saw the most weight loss,” he told Health. “We definitely can correlate improvement in osteoarthritis with weight loss, but can't say there’s a direct effect of the medication.”

Alan Beyer, MD, a board-certified orthopedic surgeon specializing in surgery of the knee and treating sports injuries, agreed that the study doesn’t prove that semaglutide directly reduces knee pain. The weight loss is likely the “real” reason for the improvement, he said.

“If you're talking about a 300-pound person, a 13% weight loss is a 40-pound weight loss. That’s a huge decrease in a person’s knee pain,” Beyer said. “So I think there was nothing in this study that suggested that the medication is what caused their knee pain to go down.”

In fact, it’s well known that being overweight is a risk factor for osteoarthritis and that weight loss improves knee pain, Beyer and Ali added. Research shows for every pound lost, there is a reduction of about four pounds of pressure on the knees with each step. So, if someone loses 40 pounds, that equates to 160 pounds less pressure on their knees per step.

“We see the improvement in osteoarthritis and knee pain in patients, no matter how they lose weight, whether they have just by diet and exercise, surgery or medications,” Ali said.

To know whether semaglutide improves knee pain independent of weight loss, researchers would need to conduct a study in which participants lose the same amount of weight through other methods, such as diet and exercise, without using semaglutide, Beyer said. If those patients also experience a decrease in knee pain, it would indicate that the weight loss, not the medication, is the cause of the pain relief.

There isn’t enough evidence to support semaglutide as a direct treatment for osteoarthritis or knee pain, Ali said. “I can’t really see the FDA saying it’s a direct treatment for osteoarthritis unless there are studies showing improvement in joint pain independent of the weight loss,” he said.

Beyer added that no licensed physician would prescribe semaglutide solely to reduce knee pain. “They’re going to prescribe Ozempic to have the patient lose weight, which in turn may decrease their knee pain,” he said. “But Ozempic is not an accepted treatment.”

If you are experiencing knee pain or symptoms of osteoarthritis, Beyer and Ali recommend talking to your healthcare provider for a proper evaluation. They can help determine the underlying cause of your knee pain and discuss the most effective treatment options tailored to your needs.

Standard treatments for osteoarthritis and knee pain typically start with lifestyle changes, such as weight loss and strengthening exercises to build muscle, which can alleviate some of the force on knee and hip joints, Beyer said.

Tylenol and nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen are also commonly used to manage pain, said Beyer. For more severe cases, steroid or lubricant injections are offered to reduce inflammation and improve joint function, Ali said.

Doctors may recommend surgical procedures, such as knee replacement, as a last resort for severe joint degeneration, Beyer added.