A hair strengthener, a cosmetic product, is a substance designed to strengthen and improve the physical integrity of hair fibers. For instance, hair masks containing keratin, a fibrous protein, are commonly used to reinforce hair structure.
Hair strengtheners hold significant relevance in hair care due to their ability to improve hair resilience, reduce breakage, and enhance overall health. Throughout history, various natural and synthetic ingredients have been employed for hair strengthening purposes, with the discovery of keratin in hair fibers marking a significant milestone.