Keratin is a type of protein which makes up large parts of one’s hair, skin, and nails and is also found in smaller amounts in glands and internal organs. Keratin is a protective protein and is more resistant to scratches or tearing than other types of proteins the body uses.As one ages natural levels of Keratin fall leading to dry hair, loss, and breakage. Supplementing with Keratin can help your hair stay full and vibrant as one ages, and has been shown to provide similar benefits to nails and skin.