An iontophoresis device may be capable of preventing or reducing the generation of gas, or the production of undesirable ions, due to an electrode reaction occurring in an electrode assembly or the alteration of an active agent due to a chemical reaction upon energization. A doping layer made of a substance such as a conductive polymer that effects an electrochemical reaction due to the doping or de-doping of an ion, may be formed in an electrode in an active electrode assembly or counter electrode assembly of an iontophoresis device.
