Embodiments provide devices, systems and methods for the transdermal delivery of chelated compounds. One embodiment provides a method for the iontophoretic transdermal delivery of a chelated iron complex for the treatment of anemia. A first patch comprising an active electrode and a chelated iron complex is applied to the skin; a second patch containing an electrode is also applied. An electrical current is then delivered to the skin from the active electrode. The chelated complex is transported across the skin via electromotive force from the current, with the iron being substantially chromogenically unreactive with the skin during transport so that there is little or no tattooing of the skin due to the formation of insoluble oxidative products.; The complex is then dissociated to release the iron where it may be bound by transferrin or ferritin for storage or metabolic use such as heme synthesis.