A water-based hair treatment composition which contains 5 to 20 parts by weight of urea, 3 to 5 parts by weight of glycerol (85-99% by volume) per 100 parts by weight of water and has a pH of 3 to 5 is described. The composition is suitable for cosmetic and medical hair treatment. The invention also relates to a process for the cosmetic treatment of hair and hair matrix using the composition.