For knee joint pain, acupuncture has been studied most extensively in people with osteoarthritis of the knee. What does the science show? Major clinical guidelines and systematic reviews generally conclude that acupuncture can provide modest pain relief and modest improvement in function for some people with knee osteoarthritis. The benefits tend to be greatest over weeks to months of treatment and may not be dramatic for everyone. Research findings suggest: Many patients report reduced pain and improved mobility compared with no treatment or usual care. When compared with “sham” (placebo-like) acupuncture, the advantage is often smaller, suggesting that both specific needle effects and non-specific factors (such as expectations, practitioner interaction, and relaxation) may contribute. Acupuncture is not known to reverse cartilage damage or cure osteoarthritis. Possible biological mechanisms Scientists have proposed several mechanisms: Release of natural pain-relieving chemicals (endorphins, enkephalins). Modulation of pain-processing pathways in the brain and spinal cord. Effects on inflammatory signaling and local blood flow. Reduction of muscle tension around the joint.