Collagen is a natural protein component of the skin that acts like a scaffold and the main building block for cells, tissues and organs. About a third of the protein content in your body is made up of collagen, which is found in the bones, muscles, and tissues of the organs.Collagen, keratin and elastin give the skin its strength, elasticity and structure.bout a third of the protein content in your body is made up of collagen, which is found in the bones, muscles, and tissues of the organs. Collagen, keratin and elastin give the skin its strength, elasticity and structure.