Collagen is the main connective tissue protein that makes up 30% of all human proteins. This is the most important structural protein. Collagen is present in most tissues and organs, including in bones, cartilage, skin, ligaments, tendons, cornea. Collagen is made of amino acids , primarily glycine and proline, as well as hydroxyproline and hydroxylysine. The main task of collagen is to connect cells together, hence it is an important building block for internal organs. The collagen has a positive effect on the cartilage matrix.