1. Home
2. Science
3. GLP-1: The Unexpected Weapon Against Knee Osteoarthritis

Since July 2025, twenty hospitals across Europe, Canada, and the United States have been testing a groundbreaking treatment for knee osteoarthritis. GLP-1 (Glucagon-Like Peptide-1), already used in diabetes care, could pave the way for a new generation of joint medications.

Knee osteoarthritis is a condition that makes descending stairs painful, limits leisurely walks, slows athletes, and affects millions worldwide. Treatment options remain limited: painkillers, anti-inflammatories, occasional injections, and, in severe cases, joint replacement surgery. To date, no therapy has been able to truly halt cartilage wear, the natural “cushion” that protects our joints.

For years, researchers and patients have dreamed of a molecule capable of slowing or even stopping the disease. That hope now lies with an unexpected candidate: GLP-1. In July 2025, the international INFLAM MOTION clinical trial began across twenty hospitals in Europe, the United States, and Canada, testing the treatment on 130 patients with knee osteoarthritis. Leading the project is one of France’s top rheumatologists, Professor Francis Berenbaum.

From Diabetes to Joints

GLP-1 is a hormone naturally produced in the gut that stimulates insulin release after a meal. This property has been the basis for recent antidiabetic and anti-obesity drugs, including liraglutide and semaglutide. Millions of patients worldwide have benefited, seeing reductions in blood sugar and body weight, sometimes accompanied by improvements in blood pressure and cardiovascular health.

However, science often brings surprises. Researchers discovered that GLP-1 receptors are also present in cartilage and the synovial membrane lining the joints. Laboratory and animal studies show that GLP-1 can reduce local inflammation, decrease the production of molecules that degrade cartilage, and potentially promote tissue repair. On paper, it offers everything osteoarthritis specialists have long sought.

It was therefore natural for Professor Francis Berenbaum and his team in Paris, pioneers in osteoarthritis research, to pursue this avenue. In July 2025, the INFLAM MOTION trial recruited its first patient. Ultimately, 130 participants aged 40 to 75 will receive either a 4P004 injection, the technical form of GLP-1 used, directly into the affected knee, or a placebo. Conducted under strict confidentiality with a double-blind design to avoid bias, the trial spans centers in France, Germany, Switzerland, Spain, the United States, and Canada.

Researchers are monitoring several outcomes. Pain is assessed via standardized questionnaires, joint function is evaluated, including walking, mobility, and stair-climbing, and imaging techniques such as MRI track changes in cartilage and the synovial membrane over several months. Scientists hope that local injections will limit side effects compared with systemic medication.

Hope on the Horizon

Why so much optimism? Obese, diabetic patients treated with GLP-1 often report reduced joint pain, likely linked to weight loss. However, in the INFLAM MOTION trial, the goal is a direct, local effect on the diseased joint: reducing inflammation, slowing cartilage breakdown, and potentially promoting tissue repair. If successful, GLP-1 could become the first disease-modifying therapy for osteoarthritis, a treatment that slows or halts the disease rather than simply masking symptoms.

Caution remains essential. Clinical trials take time. Participants will be monitored over several months, with interim assessments at four and twelve weeks, and a comprehensive evaluation expected in 2026. Researchers must confirm both efficacy and long-term safety, as medical history shows that many promising treatments fail due to unforeseen side effects or limited effectiveness.

If the results are positive, a new era could begin for knee osteoarthritis and eventually other joints. The GLP-1 trial illustrates the ingenuity of medical research, repurposing existing molecules for innovative applications. The road ahead is long, requiring further trials, validation, and likely several years before potential regulatory approval.

For patients living with osteoarthritis, every advancement provides hope for maintaining joint mobility and a life with less pain. Results from this trial, expected in 2026, will be a critical milestone for both medicine and patients.