A transdermal delivery system (1) configured to deliver an active agent to human or animal tissue, comprising a penetrative electrode (2) of one polarity that provides an electrical contact (3) beneath the stratum corneum (20)； a surface electrode (4) of the opposite polarisation to that of the penetrative electrode (2) that provides an electrical contact to the external surface of the skin (21) on the opposite side of the stratum corneum (20) to the electrical contact (3) of the penetrative electrode (2)； a dispenser (5) configured to deliver of an active agent to the external surface of the skin (21) adjacent to an electrical contact of the surface electrode (4)； a method of delivering the active agent to the tissue of a human or animal body using the transdermal delivery system (1) and an electrode assembly (10) for use in preparing the transdermal delivery system (1).
