A system for iontophoretic transdermal delivery of a non-peptidic polymeric cosmetic or therapeutic agent or of a polypeptide useful for delivery of high molecular weight cosmetic or therapeutic agents. Particularly, the present invention relates to a system that includes an iontophoresis device and a pharmaceutical composition of a non-peptidic polymeric cosmetic or therapeutic agent together with a peptide, polypeptide or protein and a pharmaceutically acceptable carrier having a pH below or above the isoelectric pH of the peptide, polypeptide or protein.