Rate controlled transdermal nicotine delivery systems are disclosed which utilize an in-line adhesive to maintain the systems on the skin. The initial equilibrated concentration of nicotine in the nicotine reservoir and the adhesive is below saturation, preferably at a thermodynamic activity no greater than 0.50, and the reservoir comprises the nicotine dissolved in a polymer with respect to which the rate controlling element of the device is substantially impermeable. In preferred embodiments the initial loading of nicotine in the reservoir is sufficient to prevent the activity of the nicotine in the reservoir from decreasing by more than about 75% and preferably no more than about 25% during the predetermined period of administration; and the thicknesses of the adhesive, rate controlling membrane and reservoir layers are selected so that at least 50% and, preferably at least 75% initial equilibrated nicotine loading is in the reservoir layer.