Glucosamine is an amino sugar, meaning it is made from a protein molecule mixed with a sugar molecule. It occurs naturally in the body, although production may decrease with age. Glucosamine is not easily obtained from food sources, so supplements provide a safe and easy way to top up. Chondroitin Sulphate is a sulphated glycosaminoglycan, composed of a chain of alternating sugars. It is usually attached to proteins as part of a proteoglycan. Chondroitin sulphates are a structural component of cartilage. Each Natures Aid Glucosamine and Chondroitin tablet provides 500mg Glucosamine and 400mg Chondroitin.