Abstract: The invention relates to delivery devices and methods for providing more uniform delivery of agents such as drugs. In some embodiments, a delivery device is provided made of one or more implantable materials having predetermined agent-permeable and agent-impermeable regions and a reservoir containing one or more active agents, either alone or in an acceptable composition, as well as methods of administering one or more agents using such a device. Also provided are methods of equilibrating such devices, so that a steady state of agent delivery can be achieved at or soon after introduction of the device to its intended location of use. Methods of use of such devices to deliver an agent are also provided.