Abstract: A hair-straightening complex consisting essentially of (i) at least one glyoxyloyl derivative formed by reacting glyoxylic acid with at least one alpha, beta or gamma amino acid and/or an amino acid analogue, where the amino acid, or analogue thereof, is not derived from an animal source, (ii) at least one organic acid, (iii) optionally, at least one humectant, and (iv) at least one monoalkyl or dialkyl ether of sorbitol or 1,4-Dianhydrosorbitol. A method of straightening hair comprising the steps of applying the above hair-straightening complex to the hair and applying a force generally perpendicular to the length of the hair using a flat surface heated at a temperature of from about 380° F. to about 450° F.