An injection device 10 comprises a housing 12 adapted to receive a syringe 14 having a discharge nozzle 18 or needle, the housing 12 includes means for biasing 26 the syringe 14 from an extended position in which the nozzle 18 extends from the housing 12 to a retracted position in which the discharge nozzle 18 is contained within the housing 12, an actuator 30, a drive acted upon by the actuator 30 and in turn acting on the syringe 14 to discharge the contents through the discharge nozzle 18, a decoupling mechanism 54, activated when the drive has been advanced to a nominal decoupling position, to allow a first component 32 of the device to move relative to a second 34, a release mechanism 52, activated when the first 32 component has reached a nominal release position relative to the second 34, to release the syringe 14 from the action of the actuator 30, whereupon the biasing means 26 restores the syringe 14 to its retracted position and a highly viscous fluid damping the movement of the first component 32 relative to the second 34, so that the release of the syringe 14 is delayed after the activation of the decoupling mechanism 54 to allow the remaining contents of the syringe 14 to be discharged before the syringe 14 is released. The first and second components of the device are first 32 and second 34 components of the drive.
