An electrotherapeutic device for passing a DC electric current through a living organism by applying a voltage to the living organism includes a battery with an internal resistance which is high enough so that changes in the resistance value of the living organism can be disregarded. Excessive flow of current is avoided even when the resistance of the living organism fluctuates. The device is safe, easy to handle, and inexpensive. It is particularly suited for use with iontophoresis; a technology by which drugs are administered using electricity.
