The present invention relates to a process for semi-permanent straightening and permanent shaping hair, especially human hair, for improved and milder semi-permanent straightening and permanent shaping. It is found out that when commonly used permanent shaping reducing composition is mixed with another composition comprising predominantly carboxylic acids, the permanent shaping effect of the composition is improved, homogeneous shaping of hair fibers is achieved and natural cosmetic properties of hair is maintained and hair may be semi-permanently straightened before such process.
