A cosmetic haircare product for the straightening of hair in shampoo format, belonging to the technical field of cosmetics, is disclosed. The shampoo is ready to be used in a single step, and comprises: Water, Sodium Laureth Sulphate, Lactic Acid, Glycolic Acid, Glyoxylic Acid, Cocamide DEA, Cocamidopropyl Betaine, Salicylic Acid, Glycol Distearate, Thioctic acid, Perfume (fragrance), Mica CI 77019, CI 77891, D-Limonene, Linalool, Propylene glycol, Hexyl cinnamal, Sodium hyaluronate, Butylphenyl methylpropional, DMDM hydantoin and Phenoxyethanol. Its method of use is also disclosed.
