Formulation (F) for the treatment of keratin fibres, especially human hair - contains an active substance combination comprising : (A) an ester of a fatty acid mono- or diglyceride (A1) and a less than 10C mono- or polyhydroxycarboxylic acid (A2), or a derivative of this ester ; and (B) a natural or synthetic vitamin (derivative). A method for preventing and/or reducing split hairs, by bringing the hair into contact with (F), is also claimed.
