A new study has found that a once-weekly injection of semaglutide, a medication originally developed for diabetes and weight loss, significantly reduces body weight and knee pain in people with obesity and knee osteoarthritis.
The research, published in the New England Journal of Medicine on October 31, suggests that semaglutide could be an effective treatment for both weight management and joint pain.
Knee osteoarthritis is a common condition that causes pain, stiffness, and swelling in the knee joints. It occurs when the protective cartilage that cushions the ends of the bones wears down over time.
Obesity is a major risk factor for osteoarthritis because excess weight puts additional strain on the joints, leading to faster cartilage breakdown and more pain. Losing weight is one of the most effective ways to reduce knee pain, but many people find it difficult to achieve significant and lasting weight loss through diet and exercise alone.
To explore whether semaglutide could help, researchers led by Dr. Henning Bliddal from Copenhagen University Hospital in Denmark conducted a large international study. They recruited 407 participants from 11 countries, all of whom had obesity and moderate knee osteoarthritis confirmed by medical imaging.
The participants were randomly divided into two groups. Two-thirds received a weekly injection of semaglutide, while the remaining third received a placebo (an injection with no active medication). Both groups were also given advice on increasing physical activity and following a lower-calorie diet.
After 68 weeks, the researchers compared changes in weight and knee pain between the two groups. The results showed that the semaglutide group lost significantly more weight—an average of 13.7% of their body weight—compared to just 3.2% in the placebo group. Participants who received semaglutide also reported greater improvements in knee pain.
Their scores on a standardized osteoarthritis pain scale dropped by an average of 41.7 points, while those in the placebo group saw a smaller reduction of 27.5 points.
In addition to pain relief, semaglutide users also experienced better physical function. Their scores on a health survey measuring daily activities improved by an average of 12 points, compared to just 6.5 points in the placebo group. Importantly, the rate of serious side effects was similar in both groups, suggesting that semaglutide was well-tolerated.
What This Means for Patients
These findings support the use of semaglutide not only for weight loss but also for reducing knee pain in people with obesity and osteoarthritis. Weight loss is known to relieve pressure on the joints, but the study suggests that semaglutide may also have direct effects on inflammation and pain pathways.
However, it is important to note that the study was funded by Novo Nordisk, the company that manufactures semaglutide. While this does not invalidate the results, independent studies may be needed to confirm the findings and assess long-term effects.
For people struggling with obesity and knee osteoarthritis, semaglutide could be a promising option to improve mobility and reduce pain.
However, as with any medication, it should be used under medical supervision and as part of a comprehensive approach that includes physical activity and dietary changes. More research will be needed to determine whether semaglutide can slow the progression of osteoarthritis or if its benefits mainly come from weight loss.
If you care about weight management, please read studies about diets that could boost your gut health and weight loss, and 10 small changes you can make today to prevent weight gain.
For more information about obesity, please see recent studies about low-carb keto diet could manage obesity effectively and results showing popular weight loss diet linked to heart disease and cancer.
The research findings can be found in New England Journal of Medicine.
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