An injection device for receiving a syringe therein and for delivering a dose of medicament from the syringe, the injection device including: a driver mechanism retainable in a primed state and releasable from the primed state for driving one or more features of the injection device forwards, a trigger mechanism including a ramped surface engaged with the driver mechanism to retain the driver mechanism in the primed state, the trigger mechanism being configured on actuation thereof to withdraw the ramped surface from engagement with the driver mechanism for release thereof.