Hair straightening with carbocisteine

A method for styling keratin fibers, in which

• (i) applying a styling agent comprising carbocisteine or a salt thereof to the keratin fibers and left thereon for a leave-in time,
• (ii) the fibers, after the leave-in time,
• are not rinsed,
• are optionally dried,
• (iii) the fibers are mechanically deformed from exposure to heat
• wherein the styling agent comprises, based on its total weight, 30 to 95 wt % water;
• and based on its total weight, 0.15 to 7.5 wt % quaternary ammonium compound(s) selected from the group
• i) tetraalkylammonium halides;
• ii) esterquats;
• iii) quaternary imidazolines of formula (Tkat2)
• in which the radicals R independently of one another each represent a saturated or unsaturated, linear or branched hydrocarbon radical having a chain length of 8 to 30 carbon atoms and A represents a physiologically acceptable anion;
• iv) amines;
• v) poly(methacryloyloxyethyltrimethylammonium) compounds
• vi) quaternized cellulose derivatives,
• vii) cationic alkyl polyglycosides;
• viii) cationized honey;
• ix) cationic guar derivatives;
• x) polymeric dimethyldiallylammonium salts and copolymers thereof with esters and amides of acrylic acid and methacrylic acid;
• xi) copolymers of vinylpyrrolidone with quaternized derivatives of dialkylaminoalkyl acrylate and methacrylate;
• xii) vinylpyrrolidone-vinylimidazolium methochloride copolymers;
• xiii) quaternized polyvinyl alcohol;
• xiv) Polyquaternium-74;
• xv) cationic alkyl oligoglucosides;
• xvi) Polyquaternium-71;
• and mixtures thereof.