MSM is an organic form of sulfur found in all living organisms. It is the fourth most abundant mineral in the human body(tenth most abundant in the known universe) and is found in every cell. Sulfur provides the chemical links needed to create collagen, which forms the and holds the molecular structure of connective tissue. It forms the disulfide bonds in connective tissue that are the links in the glycosaminoglycan chains that form cartilage. MSM is an essential nutrient, not only for connective tissue, but also for all other tissues in the human body. Unfortunately, modern food-processing methods greatly reduce nutral MSM levels in foods, so very little is obtained from the diet these days, unless your diet is rich in unprocessed milk, vegetables and grains. Sulfur is abundant in chondroitin sulfate and hyaluronic acid, two constituents that support healthy joint function.