An injection device including a housing for containing a syringe (4), a resilient member for biasing the syringe and the needle inwardly off the housing, a first coupling element moveable so as to move the needle of the syringe out of the opening and to move the dispensing piston of the syringe towards the end surface, a mechanism operable to release the syringe, a drive coupling so as to transfer movement of said first coupling element to the dispensing piston wherein the mechanism is triggered to release the syringe and includes components to delay release of the syringe until a predetermined period after being triggered and/or the mechanism includes an inertial mass moveable with the first coupling element and drive coupling and a release member actuable by the inertial mass to release the syringe such that when the dispensing piston releases the end surface of the syringe and the first coupling element and drive coupling stop moving, the inertial mass continues to move so as to actuate the release member to release the syringe.
