Described is an autoinjector (1) comprising a case (2), a motor (15) adapted to rotate a drive gear (20), and a curvi-linear plunger (18) adapted to mate with the drive gear (20). The plunger (18) includes a distal end with a resilient flange, which in a non-deflected state, abuts a proximal collar (5.2) of a syringe (4), and, in a deflected state, advances through the proximal collar (5.2) and engages a stopper (19) in the syringe (4).