Disclosed is a reusable auto-injection system that can be reset by connection to a base station to provide easier and safer operation for unskilled users. The injection system comprises an injection device with a syringe comprising a fluid container and a discharge nozzle or needle. A housing is adapted to receive the syringe that is movable between a retracted position in which the syringe is wholly contained in the housing and an extended position in which at least part of discharge nozzle extends out of the housing. A drive and an actuator mechanism of a rechargeable battery or capacitor operated motor connected to the drive connected to the drive having an unactuated state in which it does not act on the drive and an actuated state in which it has acted on the drive and moved the syringe to its extended position and expelled fluid from the fluid container. The trigger mechanism operates to release the actuator mechanism to move the syringe to its extended position and expel fluid from the fluid container. The base station connects to the housing of the injection device and resets the actuator mechanism from its actuated state to its unactuated state when the base station is connected with the housing of the injection device so that further actuation of the actuator mechanism can take place.
