A blister piercing element for puncturing the lid of a blister containing a dose of medicament for inhalation by a user is disclosed. It comprises a body having a surface and an opening in the surface for the passage of air, or for the passage of medicament entrained in air, through the body. The body includes a pair of spaced cutting teeth upstanding from the surface in spaced side-by-side relation, each cutting tooth projecting in cantilevered form over said opening and each having a distal cutting edge at a free end remote from said surface. The distal cutting edge of each tooth is configured to initiate a slit in a blister lid when pressure is applied to a blister lid by the teeth and the teeth are spaced from each other so that separate slits cut by the distal cutting edge of each tooth propagate in a direction toward each other between the teeth as the teeth continue to penetrate a blister lid. The pair of spaced cutting teeth form a single slit in a blister lid that defines a single flap which is folded into the blister by the teeth.