Glucosamine is an aminosaccharide found in connective tissue, cartilage, and the synovial fluid that lubricates joints. Glucosamine supplements have been studied extensively for its therapeutic potential in joint disorders, osteoarthritis, and rheumatoid arthritis. Studies have highlighted several chondroprotective effects of glucosamine including direct stimulation of chondrocytes, incorporation of sulfur into cartilage, and protection against degradative processes within the body through altered gene expression and downregulation of inflammatory mediators.
There is evidence that long-term administration of glucosamine may delay structural joint changes, suggesting potential benefits beyond just symptom control when used early in the management of osteoarthritis. Multiple randomized control trials have found a 5-15% reduction in severe joint space narrowing when glucosamine is compared to placebo.Furthermore, there is evidence that supports the supplement combination of glucosamine and chondroitin for knee osteoarthritis. Analysis of the Osteoarthritis Initiative (OAI) progression evaluated 600 patients who took glucosamine and chondroitin sulfate for knee OA and found that they had a less degradation of cartilage volume over 2 years compared to placebo.