An injection device comprising: a housing adapted to receive a syringe having a relatively wide reservoir portion and a relatively narrow discharge nozzle, so that the syringe is movable between a retracted position in which the discharge nozzle is contained within the housing and an extended position in which the discharge nozzle extends from the housing through an exit aperture; a drive that acts upon the syringe to advance it from its retracted position to its extended position and discharge its contents through the discharge nozzle; and a syringe carrier for carrying the syringe as it is advanced and restraining its advancement beyond its extended position, wherein the syringe carrier comprises an annular collet having an internal diameter that is smaller than an outer diameter of the reservoir portion of the syringe, wherein the annular collet is adapted to support the syringe between the reservoir portion and the discharge nozzle; and, the injection device further comprising: means for biasing the syringe from its extended position to its retracted position; a support for carrying the means for biasing the syringe, wherein the syringe carrier further comprises means for bearing against the support and in which the means for bearing comprises a portion having an external diameter which is greater than the external diameter of any portion of the syringe carrier situated between the means for bearing and the discharge nozzle. a housing adapted to receive a syringe having a relatively wide reservoir portion and a relatively narrow discharge nozzle, so that the syringe is movable between a retracted position in which the discharge nozzle is contained within the housing and an extended position in which the discharge nozzle extends from the housing through an exit aperture; a drive that acts upon the syringe to advance it from its retracted position to its extended position and discharge its contents through the discharge nozzle; and a syringe carrier for carrying the syringe as it is advanced and restraining its advancement beyond its extended position, wherein the syringe carrier comprises an annular collet having an internal diameter that is smaller than an outer diameter of the reservoir portion of the syringe, wherein the annular collet is adapted to support the syringe between the reservoir portion and the discharge nozzle; and, the injection device further comprising: means for biasing the syringe from its extended position to its retracted position; a support for carrying the means for biasing the syringe, wherein the syringe carrier further comprises means for bearing against the support and in which the means for bearing comprises a portion having an external diameter which is greater than the external diameter of any portion of the syringe carrier situated between the means for bearing and the discharge nozzle. means for biasing the syringe from its extended position to its retracted position; a support for carrying the means for biasing the syringe, wherein the syringe carrier further comprises means for bearing against the support and in which the means for bearing comprises a portion having an external diameter which is greater than the external diameter of any portion of the syringe carrier situated between the means for bearing and the discharge nozzle.