The invention concerns the use of a composition comprising at least one yeast (Saccharomyces cerevisiae) peptide hydrolysate as an active agent for strengthening hair and improving hair health. The invention also concerns the use of this novel active agent for making a dermo-pharmaceutical composition intended to stimulate hair growth or to prevent hair loss. The invention furthermore refers to a cosmetic treatment method intended to stimulate hair growth or counteract hair loss and counteract external aggressions affecting the hair.
