The two-component hair treatment product consists of one component (A) and another component (B). Component (A) contains an acid and component (B) contains a base. Less than 3 g of the base and/or acid are soluble in 100 ml of water at 20.degree. C. The acid is preferably a dicarboxylic acid, such as sebacic, dodecanoic dicarboxylic acid or tetradecanoic dicarboxylic acid. The base is preferably ammonia, an alkyl amine or an alkylol amine. Prior to use in a method of permanent hair shaping or hair care, the components are mixed with each other to form a ready-to-apply mixture having an automatically continuously or gradually changing pH that changes within from one to 60 minutes so that damage to the hair due to high pH is avoided. For permanent shaping of hair the initial pH of 8 to 13 falls from about 1 to 4 pH units within from 10 to 30 minutes after mixing the components.