Glucosamine is an essential substrate for the formation of glycoaminoglycans (GAGs) and proteoglycans which are the main components of cartilage tissue. GAGs and proteoglycans trap and hold water forming a dense fluid cushion within the joint and thus provide lubrication and shock absorption. MSM (Methylsulfonylmethane) is a natural source of organic sulfur a mineral necessary for the production of proteoglycans.* NOW unique and synergistic formula is suitable for vegetarians because it contains only Glucosamine from a vegetarian source and not from shellfish.