Abstract: There is provided an electro-therapeutic device having first and second electrodes or probes for making electrical contact to the body of an individual. The device has voltage supplying means for supplying an alternating output voltage across the electrodes to pass an alternating current through the body of the individual, and the voltage supply means are adapted for controlling the frequency of the output voltage so that the output voltage frequency is automatically changing in time between a low frequency and a high frequency. The voltage supply means may be adapted for controlling the frequency of the output voltage so that the output voltage frequency is changing between a low frequency and a high frequency at regular time intervals.