A blister strip advance mechanism comprising: an indexing gear train; drive means configured to drive said indexing gear train; and a hub (230) comprising a recess shaped to engage a first blister of a blister strip, said hub being rotatable by the indexing gear train to engage the first blister in said recess and move the engaged blister strip such that a second blister is moved to a dosing position at which the second blister (130) can be emptied; wherein the indexing gear train is configured to temporarily disengage said drive means from the hub when the second blister is in said dosing position. Also: a dosing mechanism comprising said blister strip advance mechanism; an inhaler comprising said dosing mechanism; a method for advancing a blister strip and a method for dosing a medicament comprising said method for advancing a blister strip.