Is there a term from the field of dermatology and cosmetics that you do not understand? Would you like to know what it means? View the full definition from the La Roche-Posay glossary.
Keratin is the chief structural constituent of hair. It is a protein with high content of cystine, a sulphur amino acid. The hair fibre forms during the keratinization process, when keratinocytes, which are cells found in the hair bulb, multiply, fill with keratin, then die and harden.