A needle-free injector is disclosed, the injector comprising a nozzle assembly disposed at a front end of the needle-free injector, wherein the nozzle assembly comprises a piston within a nozzle and adapted to extract and contain a volume of fluid to be injected. The injector also comprises a power house adapted to exert an injection force on the piston to inject the fluid from the nozzle. The injector further comprises a release system, wherein the release system comprises a locking member adapted to move between a locked position and an unlocked position, and a releasing member adapted to move the locking member from the locked position to the unlocked position upon exertion of an unlocking force on the releasing member by a user during operation. While the locking member is in unlocked position, the user can activate the power house by exerting a counter force on the injector. The unlocking force and the counter force are in the same direction as the injection force. A method of releasing a needle-free injector is also disclosed.
