It is considered that taking glucosamine in conjunction with chondroitin may be beneficial. Chondroitin is an glycoaminoglycan (chain of repeating amino sugars) normally marine sourced from cartilage. Inferior chondroitin may be sourced from bovine origin. SGK feel it is always important to ensure that their chondroitin is in excess of 90% Pure Marine sourced, & that every batch has been tested to Trading Standards methods. Chondroitin attracts fluid into the joint bringing valuable nutrients with it, which is very important as there is no blood supply to cartilage. This may help to cushion the joint also & inhibit derivative enzymes & provide structure. It is recognised that 500mg of glucosamine combined with 400mg of chondroitin is an excellent ratio for effecting joint repair. You need to be sure how much of the purely active ingredient (glucosamine sulphate) you are taking, not the weight of the whole tablet combined with the mineral salt. In most cases 665 mg of Glucosamine Sulphate 2kcl provides 500mg of Glucosamine Sulphate.