The present invention is to provide a new technology that can prevent skin or hair from oxidant stress caused by reactive oxygen or free radical. The present invention is to provide a cosmetic kit and hair treatment agent kit. The cosmetic kit cosists of agent A, agent B and agent C, the A agent containg magnesium hydride, the agent B containg a substance that is acidic in aqueous solution, and the agent C contains water. Mix the agent A, agent B and agent C to obtain cosmetic for use. The hair treatment agent kit cosist of agent A, agent B and agent C.本發明提供一種新型技術,其可有效地防止活性氧或自由基對皮膚或毛髮造成之氧化壓力。本發明提供一種化妝料用套件及毛髮處理劑用套件,該化妝料用套件包含含有氫化鎂之A劑、含有水溶液顯示酸性之物質之B劑、及含有水之C劑,且於使用時將A劑、B劑及C劑混合而獲得化妝料;該毛髮處理劑用套件包含含有氫化鎂之A劑、含有水溶液顯示酸性之物質之B劑、及含有水之C劑。
