A device releases a fluid active substance, the device has at least one hollow space containing the fluid active substance, whereby the device contains water and a reducing agent, which are or can be made to be in communication such that a chemical reaction of the water and the reducing agent produces a gas and the gas effectively communicates with the fluid active substance such that the gas pressure thus generated presses the fluid active substance out of at least one opening of the hollow space out of the device. A medical implant incorporates the device, and a method releases a fluid active substance from a hollow space of the medical implant, in which a gas is produced through a chemical reaction of liquid water and a reducing agent, and the resulting gas pressure is used to expel the fluid active substance out of at least one opening of the hollow space.