The present specification provides for an oxidative hair treatment agent. The agent includes, in a cosmetic carrier, a combination of at least one oxidizing agent and at least one modified starch. The modified starch is modified by propylene oxide, has an average molecular weight between 50 and 2500 kiloDaltons (kDa), and has a propylene oxide content between 0.1 and 20.0 weight percent (wt %) based on the weight of the modified starch.