Hydrolyzed keratin protein is derived from keratin, a fibrous structural protein found in human hair, skin, and nails, as well as in the feathers, hooves, and horns of animals. Hydrolyzed keratin is a processed form of keratin that has been broken down into smaller molecules through hydrolysis, a chemical process involving the use of water. This process makes the protein more soluble and easier for the skin and hair to absorb.