Glucosamine Plus MSM helps you maintain healthy structure and function of cartilage in your joints with Joint Fluid (Hyaluronic Acid), the main component of synovial fluid, which helps lubricate joints to allow smooth, quiet movement. Glucosamine Hydrochloride (HCl) has the highest potency of active Glucosamine. Glucosamine HCl is about 83% Glucosamine, while most brands use Glucosamine Sulfate that is only about 65% Glucosamine.