An auto-injector for administering a dose of a liquid medicament, comprising - an elongate housing arranged to contain a syringe with a hollow needle and a stopper for sealing the syringe and displacing the medicament, the housing having a distal end and a proximal end with an orifice intended to be applied against an injection site, wherein the syringe is slidably arranged with respect to the housing, - a drive spring capable of, upon activation: - pushing the needle from a covered position inside the housing into an advanced position through the orifice and past the proximal end, and - operating the syringe to supply the dose of medicament, and - activating means arranged to lock the drive spring in a compressed state prior to manual operation and capable of, upon manual operation, releasing the drive spring for injection, wherein the elongate housing comprises two portions (2.1, 2.2) connected by a hinge, the portions (2.1, 2.2) rotatable about the hinge relative to each other between an aligned position and a maximum opening angle, wherein the drive spring is be compressed by rotating the portions (2.1, 2.2) out of the aligned position towards the maximum opening angle, wherein the activating means are arranged to lock the drive spring in the compressed state when the portions (2.1, 2.2) are rotated at least almost to the maximum opening angle and wherein a loading bay for holding the syringe is arranged in one of the portions (2.2), the loading bay being accessible from its distal end for loading or unloading the syringe when the portions (2.1, 2.2) are rotated out of the aligned position, wherein a lever is attached with one end to a fixed first pivot in the one portion (2.2), wherein the other end of the lever is attached to a second pivot arranged at a sliding shuttle in the other portion (2.1), the sliding shuttle translatable in longitudinal direction of the other portion (2.1) between a maximum proximal position when the portions (2.1, 2.2) are aligned and a maximum distal position when the portions (2.1, 2.2) are rotated at least almost by the maximum opening angle, wherein a drive collar arranged at a proximal end of the drive spring is engageable by the sliding shuttle in order to compress the drive spring, characterized in that the one portion (2.2) is a proximal portion (2.2) and the other portion (2.1) is a distal portion (2.1), wherein the drive spring is a single drive spring used for providing axial motion for advancing the syringe and injecting a dose of medicament. - an elongate housing arranged to contain a syringe with a hollow needle and a stopper for sealing the syringe and displacing the medicament, the housing having a distal end and a proximal end with an orifice intended to be applied against an injection site, wherein the syringe is slidably arranged with respect to the housing, - a drive spring capable of, upon activation: - pushing the needle from a covered position inside the housing into an advanced position through the orifice and past the proximal end, and - operating the syringe to supply the dose of medicament, and - activating means arranged to lock the drive spring in a compressed state prior to manual operation and capable of, upon manual operation, releasing the drive spring for injection, wherein the elongate housing comprises two portions (2.1, 2.2) connected by a hinge, the portions (2.1, 2.2) rotatable about the hinge relative to each other between an aligned position and a maximum opening angle, wherein the drive spring is be compressed by rotating the portions (2.1, 2.2) out of the aligned position towards the maximum opening angle, wherein the activating means are arranged to lock the drive spring in the compressed state when the portions (2.1, 2.2) are rotated at least almost to the maximum opening angle and wherein a loading bay for holding the syringe is arranged in one of the portions (2.2), the loading bay being accessible from its distal end for loading or unloading the syringe when the portions (2.1, 2.2) are rotated out of the aligned position, wherein a lever is attached with one end to a fixed first pivot in the one portion (2.2), wherein the other end of the lever is attached to a second pivot arranged at a sliding shuttle in the other portion (2.1), the sliding shuttle translatable in longitudinal direction of the other portion (2.1) between a maximum proximal position when the portions (2.1, 2.2) are aligned and a maximum distal position when the portions (2.1, 2.2) are rotated at least almost by the maximum opening angle, wherein a drive collar arranged at a proximal end of the drive spring is engageable by the sliding shuttle in order to compress the drive spring, characterized in that the one portion (2.2) is a proximal portion (2.2) and the other portion (2.1) is a distal portion (2.1), wherein the drive spring is a single drive spring used for providing axial motion for advancing the syringe and injecting a dose of medicament. - pushing the needle from a covered position inside the housing into an advanced position through the orifice and past the proximal end, and - operating the syringe to supply the dose of medicament, and - activating means arranged to lock the drive spring in a compressed state prior to manual operation and capable of, upon manual operation, releasing the drive spring for injection,