The invention relates to an antiperspirant cosmetic agent which includes at least one specific chitosan and which is free of aluminum-containing compounds, in particular free of halides and/or hydroxy halides of aluminum and/or zirconium. The present invention further relates to the use of a specific chitosan and to a non-therapeutic method for reducing body perspiration. Adding or using the at least one specific chitosan ensures that the sweat gland(s) is/are effectively influenced, thus resulting in a significant reduction in underarm perspiration even in the absence of antiperspirant aluminum-containing compounds.