A simulated cigarette device with a substantially cylindrical cigarette-like shape comprising a reservoir of a pressurized composition including an inhalable substance and a propellant. A refill valve is in communication with the reservoir via which the reservoir is refilled. A breath-activated valve selectively controls the flow through a reservoir outlet and hence through an inhaling outlet in the device. The size of the reservoir, the pressure within the reservoir and the size of the reservoir outlet at its narrowest point are arranged so that, when the breath-activated valve is fully opened, the reservoir will discharge in less than 30 seconds.