Collagen peptide is an extracellular protein. Consisting of two or more amino acids — a protein peptide. The absorption of human body is carried out in the form of peptides, and the absorption rate of edible protein peptides can reach 100%. It is rich in glycine and proline needed by human body. There are 18 kinds of amino acids such as hydroxyamino acid. Collagen is the most important component of extracellular matrix.