Glucosamine is produced naturally in the body, although there are no major food sources of this substance. A major structural component within joint tissue of cartilage, tendons and ligaments and is the starting point of the synthesis of several important macromolecules including glycoproteins, glycolipids and glycosaminoglycans. These macromolecules can be found in the synovial fluid, cartilage, tendons, ligaments and muscles.