the present invention relates to a dose setting and expelling device comprising a drive member and a dose setting mechanism which simultaneously sets a given dose and stores the energy necessary for a subsequently driving the drive member in order to expel a dose of medicine from an injection device . according to the invention the dose setting mechanism allows adjustment in both directions , such that a given set dose can be reduced or cancelled by reversing the input motion , typically by rotating a setting member backwardly , this in contrast to the known devices which either requires an additional release mechanism or which cannot be reversed at all .