Composition for hair protection or hair strengthening

A hair cosmetic composition for hair protection, damaged hair repair, or hair strengthening, comprising:

• a peptide or a peptide derivative in an amount effective to protect hair, repair damaged hair, or strengthen hair,
• wherein the peptide is KCV (Lys-Cys-Val), and
• wherein the peptide derivative is KCV having a palmitoyl group bound to the N-terminus (palmitoyl-Lys-Cys-Val),
• wherein the hair is head hair, eyebrows, and/or eyelashes;
• and
• wherein the hair cosmetic composition is selected from the group consisting of hair shampoo, hair rinse, hair conditioner, hair cream, hair oil, hair lotion, hair tonic, hair mist, hair treatment, hair serum, hair mousse, hair wax, hair essence, hair spray, eyebrow serum, eyebrow essence, eyelash serum, and eyelash essence.