Creating a permanent wave in hair comprises contacting the hair with a first permanent wave liq. (X) which contains an S-(2-aminoethyl)isothiuronium salt of formula NH2CH2CH2S-C(NH)NH2.nHX (I) as a reducing agent at a pH of 7.0-10.0 and then setting the wave with the aid of a second liq. (Y) contg. an oxidising agent. X = Cl or Br; and n = 1-2. Also claimed is (a) (X); (b) (Y) contg. a taurine deriv. (II) or its salt, comprising taurine with one or more halogen atoms bonded to the nitrogen atom as an oxidising agent; and (c) method for creating a permanent wave in hair by bringing it into contact with (X) and then setting the wave with (Y) contg. (II).
