Abstract: Keratinous fiber treatment formulations and methods of providing a long lasting set in keratinous fibers such as hair by applying a polymer system to the hair which provides a stable set to the hair which will last at least until the hair is thoroughly washed. The set is made more permanent by incorporating a reducing agent such as L-cysteine into the polymer system and allowing the system to air oxidize over time or optionally applying a second chemical oxidizing system to the treated hair which will accelerate the oxidation process and the setting rate of the hair.