Now Vegetarian Glucosamine & MSM combines two well-known joint support ingredients in a vegetarian/vegan friendly formula that does not include shellfish-derived Glucosamine.* Glucosamine is an essential building block for the formation of glycosaminoglycans (GAGs) and proteoglycans, the main components of cartilage tissue.* These compounds attract water to form a joint cushion, providing lubrication and shock absorption.* MSM (Methylsulfonylmethane) is an organic form of sulfur, a mineral necessary for the production of GAGs and proteoglycans.*.