Fingernails & Toenails: What Are They Made Of? - Keratin Explained

Fingernails and toenails are not made of hard skin. They are made of a strong, flexible protein called keratin, which is also found in hair and the outermost layer of skin. Keratin is produced by cells in the nail matrix, which is located at the base of the nail. The matrix cells push new keratin cells upward, replacing the older cells that are worn away.