Keratinocytes are living cells present in your skin, which produce a protective layer to provide flexibility and strength to the skin, to prevent excessive outflow of water and to keep external materials out of the body. The protein strand that makes this layer is tough and shaped like a triple-helix and is referred to as keratin. It is the primary ingredient present in hair, nails, skin and enamel of tooth. Keratin can also be found in your internal organs and glands. Keratin is a protective protein, less prone to scratching or tearing than other types of cells your body produces.

Keratin can be derived from the feathers, horns, and wool of different animals and used as an ingredient in hair cosmetics. Since keratin is the structural building block of your hair, keratin supplements, products, and treatments can help strengthen your hair and make it look healthier and more beautiful.

The technical keratin definition is that it is an insoluble protein found in the epidermal tissues of vertebrae (1). Keratin proteins are tough and fibrous; that’s because they form the structural framework of the cells that line the surfaces of organs, canals, and cavities (these are called epithelial cells). Keratinization is the process in which cells from under the skin convert into hair and nails.