A transdermal therapeutic system (TTS) that is essentially composed of two compartments and is provided with activatable oversaturation and controlled permeation promotion. The invention more particularly relates to a TTS wherein an oversaturated active ingredient solution is produced in an active-substance-containing polymer matrix when the system is applied to the skin, caused by the controlled supply of one or several substances promoting the permeation of the pharmaceutical active ingredient; to the two compartments from which the inventive transdermal therapeutic system is assembled; and to the production of the transdermal therapeutic system from the two compartments.