Glucosamine - an essential precursor of the GAG chondroitin sulphate (a key structural component of cartilage) and hyaluronic acid (found in joint lubrication - synovial fluid, the fluid in the eye and loose connective tissue. MSM - because sulphur is needed for virtually every function in every cell of the body, it's properties are too numerous to list in their entirety. It is present in proteoglycans which are large molecules which interlink and bind cells together. these include chondroitin sulphate and keratin sulphate and are found in connective tissues (including cartilage, ligaments, tendons), blood vessels, skin, nails and hair. Chondroitin Sulphate - together with hyaluronic acid, chondroitin forms a substance known as aggrecan which gives the cartilage shock adbsorbing properties. Aggrecan and collagen act together to form tough deformable cartilage which always returns to it's original shape. This provides an effective way seperating and protecting two articulating bones. Chondroitin sulphates are a component of cartilage which help to attract water maintaining the compressibility / elasticity and fluidity of joint movement. they are also components of the walls of blood vessels and are thus important in maintaining vascular health. Ingredients Glucosamine Sulphate KCL (from shellfish), Bulking agent: Microcrystalline Cellulose, Methyl Sulphonyl Methane, Chondroitin Sulphate, Croscarmellose Sodium, Anti-caking agent: Silicon Dioxide, Magnesium Stearate, Glazing agent: Hydroxpropylmethylcellulose. Three tablets provide: Glucosamine Sulphate KCL 1987mg providing: Glucosamine Sulphate 1500mg of which Glucosamine 1176mg, Methyl Sulphonyl Methane 1500mg, Chondroitin Sulphate 300mg (Three tablets per day of this amount of glucosamine reflects the amount used in research)