Exemplary embodiments provide dispensers and delivery devices that release their contents at sustained rates. An exemplary device may include one or more reservoirs for holding a solid, semisolid, liquid or gaseous substance that may be released outside the device. Exemplary devices enable sustained release of their contents over a predetermined period of time, for example, up to a month or more. Exemplary devices also enable release of the contents according to, for example, predetermined release rates and profiles customized for the use of the device. Each reservoir of the device may include one or more apertures through which the contents may be released outside the reservoir. Each aperture may be covered by one or more porous membranes to allow sustained release of the contents of the reservoir.
