A transdermal patch for the treatment of iron deficiency including a drug reservoir layer containing an hematinic substance; a rate-controlling membrane secured to said reservoir layer; and a contact adhesive secured to said rate-controlling membrane, wherein said hematinic substance is selected from the class consisting of ferrous sulfate, ferrous lactate, ferrous iodide, ferrous gluconate, ferrous fumarate, ferrous citrate, ferrous carbonate saccharated, ferrous carbonate mass, ferronascin, ferroglycine sulfate, and ferrocholinate.