Did you know that collagen is the most abundant protein in the human body? It makes up about 25-30% of all protein in our bodies. Collagen is high in glycine, proline, and arginine which your body, incidentally, needs to produce more collagen. These important amino acids are not found in large supply in dietary protein such as chicken or beef. So, even if you eat an adequate amount of protein on a regular basis, you could still be lacking in the collagen department.