A system and method for transdermally delivering a biologically active agent comprising one or more electrodes having stratum corneum-piercing projections and a circuit that delivers an electrical signal to the electrodes to electroporate a cell membrane. Preferably, the system is configured to generate homogeneous electrical fields and, more preferably, to generate spherically or semispherically symmetrical electric fields. Methods of the invention include applying a first electric signal to facilitate transdermal transport of the agent and applying a second electric signal to facilitate intracellular transport of the agent.