Glucosamine is the building block of cartilage joint tissue double strength coated capsules glucosamine is naturally found in the joints of the body but rarely found in natural food sources it is a building block of cartilage and joint tissue glucosamine is the basis 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