The invention relates to a method for restructuring keratin fibers, whereby a keratin fiber is contacted with (a) an aqueous preparation of at least one polysulfide of formula (I), wherein R represents hydroxy or the group (II), R represents hydrogen or the group (III), A is a bond or a bivalent saturated or mono- or polyunsaturated aliphatic or aromatic hydrocarbon group having 1 to 20 carbon atoms, which can be substituted by one or more halogen, hydroxy or carboxy groups and whereby the shortest bond between the carbonyl groups adjacent to group A consists of up to 12 carbon atoms, and wherein R and R are the same or different and are selected from R O— and (IV), wherein R represents hydrogen or an alkyl group having 1 to 6 carbon atoms, n is an integer of from 1 to 100, and whereby one or more carboxyl groups may be present in the form of one or more of its/their salts, and, either simultaneously or successively, a reducing agent, and then (b) with an oxidant. The invention also relates to preparations for use in the inventive methods.