Participants’ knee pain levels were measured on a scale from 0 to 100, with higher scores indicating more severe pain. After six months, those taking metformin reported an average pain reduction of 31.3 points, compared to an 18.9-point reduction in the placebo group — a statistically significant and clinically moderate improvement
A widely-used diabetes medication could soon offer relief to millions suffering from knee osteoarthritis (OA) and obesity, according to a new study. Researchers from Monash University in Australia have found that metformin, a drug commonly prescribed to manage type 2 diabetes, can significantly reduce knee arthritis pain in people without diabetes and potentially delay the need for knee replacements.
The findings, published in the journal JAMA, suggest that metformin may be an affordable and effective treatment alternative for knee OA patients who struggle with limited mobility and chronic pain.
“Metformin is a potentially new and affordable way to improve knee pain in those with knee OA and overweight or obesity,” said lead researcher Professor Flavia Cicuttini, who heads the Musculoskeletal Unit at Monash University.
The six-month randomized clinical trial involved 107 participants — 73 women and 34 men — with an average age of 60. None of the participants had diabetes. They were divided into two groups: one group received up to 2,000 mg of metformin daily, while the other was given a placebo. The trial was conducted entirely via telehealth, making it one of the few community-based studies of its kind.
Participants’ knee pain levels were measured on a scale from 0 to 100, with higher scores indicating more severe pain. After six months, those taking metformin reported an average pain reduction of 31.3 points, compared to an 18.9-point reduction in the placebo group — a statistically significant and clinically moderate improvement.
Knee osteoarthritis is one of the most common causes of disability worldwide, particularly among older adults. Current treatment options typically include lifestyle modifications such as exercise and weight loss, which many patients find difficult to maintain. Medication options like paracetamol, topical anti-inflammatory creams, and oral anti-inflammatory drugs often provide only minor benefits and may pose safety concerns for long-term use.
Professor Cicuttini emphasized the urgent need for better non-surgical treatment alternatives. She noted that the lack of effective therapies often pushes patients and doctors toward early knee replacement surgeries, even though such surgeries are ideally reserved for more advanced stages of OA.
“This leads to major challenges in managing knee osteoarthritis, including the rising rates of knee replacements performed earlier than necessary,” she said.
According to Cicuttini, metformin’s effectiveness likely stems from its impact on low-grade inflammation and other metabolic pathways crucial in the progression of knee osteoarthritis. “Metformin works in a number of ways on the knee, including affecting low-grade inflammation and other metabolic pathways that are important in knee OA,” she explained.
She also highlighted the advantages of metformin being a low-cost, well-tolerated medication. By alleviating knee pain and enabling greater physical activity, the drug could delay the need for knee replacement surgeries, allowing patients to maintain their quality of life longer before considering surgical interventions.
“If people on metformin have less knee pain and are able to do more physical activity, then knee replacements can wait,” Professor Cicuttini said. Despite the promising results, the researchers cautioned that larger and longer-term studies are needed to confirm the findings. The relatively small sample size of 107 participants calls for broader trials to fully understand metformin’s potential as a standard therapy for knee osteoarthritis in overweight and obese populations.
Still, the study opens the door to a new, practical treatment avenue that could benefit millions worldwide who are grappling with the double burden of obesity and knee osteoarthritis.
