Myristyl hexapeptide-16 is classified as a protein signal peptide. It enhances the production of skin protein called keratin. Keratin is the basic skin protein and the key structure of skin, nails and hair. It forms the outer layer of the skin and plays a major role in protecting the lower layer of the skin. Hexapeptide also has the property of retaining moisture. Therefore, it will not let the water evaporate and keep it on the skin during use. Insen Myristyl hexapeptide-16 is usually used together with pentapeptide-15 to improve the growth of eyelashes.