An autoinjector includes a housing for receiving in use in a generally longitudinal loading direction a syringe assembly including a syringe carrier and a syringe, the syringe including a syringe body having a slideable internal piston for expressing a dose contained in the body through a needle at a forward end thereof a drive mechanism for providing drive for operation of the autoinjector and being disposed generally within the housing and including a mechanical energy source and a winder element for being rotated to charge the energy source, and an input transmission train operational between the syringe assembly and the winder element in use, whereby loading of the syringe assembly into the housing rotates the winder element to charge the energy source.
