noun
- a tough, fibrous protein that is the main structural component of hair, nails, and the outer layer of skin
Usage: commonly used in biology and cosmetics
Examples
- Keratin is the protein that makes your hair strong and shiny.
- Nails are made primarily of keratin.
- Many shampoos contain keratin to repair damaged hair.
- The outer layer of your skin contains keratin for protection.
- Keratin treatments can help smooth frizzy hair.