An injection device (110) comprises a housing (112) having a syringe (114) with a discharge nozzle (118). 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. There is a syringe cap (180) for enclosing the discharge nozzle. The syringe cap is removable from the syringe by rotation relative to the syringe. A syringe carrier (150) in the housing is adapted to restrain rotation of the syringe relative to the housing as the cap is removed.