Described herein is a method for treating hair including: (a) putting the hair in a desired shape； (b) before and/or after the hair is put in the desired shape, applying a reducing composition to the hair including: (i) from about 2.5% to about 15% of a cationic mercapto amino pyridinium compound or a cationic dimercapto amino pyridinium compound； (ii) from about 4% to about 10% of a buffering system； and (iii) from about 50% to about 93.5% of a solvent； (c) rinsing the reducing composition from the hair； (d) applying an oxidizing composition to the hair including: (i) from about 0.5% to about 12% of an oxidizing agent； and (ii) from about 80% to about 97% of a solvent； and (e) rinsing the oxidizing composition from the hair. The reducing composition has a pH of from about 8 to about 10.5；L'invention concerne une classe chimique de thiols inodores qui peuvent servir comme agents réducteurs. Cette classe chimique implique des thiols qui peuvent être utilisés en tant qu'agents réducteurs pour des traitements de mise en forme permanente, des compositions dépilatoires et d'autres applications. Les thiols inodores sont des thiols ayant un sel d'ammonium quaternaire hétérocyclique dans leur molécule.
