An injection device for delivering an injection comprises a housing having a longitudinal axis, a proximal end and a distal end, the housing being arranged such that the injection is delivered from its distal end； and a release mechanism comprising an impediment, the release mechanism being moveable between a first position, in which the impediment is in an impeding position so as to impede the delivery of the injection, and a second position, in which the impediment is in a non-impeding position so as to not impede the delivery of the injection, wherein the force required to move the release mechanism from the first position to the second position varies with the distance moved by the release mechanism, the variation in the force required with distance being represented by a force profile, which is non-linear.
