Source Naturals Sodium Free Glucosamine Sulfate Powder -- 4 oz

What the brand says

Glucosamine sulfate is a naturally occurring amino sugar. Amino sugars are key constituents of larger compounds called glycosaminoglycans and glycoproteins, which enable cells in tissues to hold together. They are necessary for the construction and maintenance of virtually all connective tissues and lubrication fluids in the body-tendons, ligaments, cartilage, bone matrix, skin, joint fluid, intestinal lining and mucous membranes.