Keratin is a structural protein and the main component of hair, horns, feathers, wool, and the stratum corneum of the skin. The distinctive feature of this protein compared to other similar proteins is its richness in the amino acid cysteine. The amount of cysteine in human hair is between 14-15%, which contributes to the strength of the hair. Due to these properties, keratin functions as both an internal structural protein and an external protective protein. Additionally, keratin helps reduce water evaporation from the epidermal layer. This dietary supplement is rich in amino acids and crude protein, making it suitable for use in the formulation animal feed for livestock, poultry, and aquatic species.