Collagen is the body's natural protein. It is the most abundant form of natural protein found in the body. It is the essential structural component of all connective tissue. So collagen accounts for between one quarter and one third of the body's protein. Collagen makes up 75% of the body's skin tissue and about 90% of dermal volume. The skin is the body's largest organ. Collagen naturally contains 15% glucosamine sulphate and 15% chondroitin sulphate. Collagen is the most abundant structural protein found in cartilage, muscle, tendons, ligaments and bones.