A dry powder inhaler (2) comprises a housing (6, 8) including a mouthpiece (10) and a cover (11, 12) movably mounted to the housing (6, 8). The cover (11, 12) is movable between an open configuration of the inhaler (2) in which the mouthpiece (10) is exposed for use and a closed configuration of the inhaler (2) in which the mouthpiece (10) is enclosed. In the open position, the cover (11, 12) at least partly defines an inlet aperture (71) to an inhalation air flow path leading through the inhaler (2) and communicating with the mouthpiece (10). The inlet aperture (71) is positioned in such a way that makes it difficult for a user to obstruct it when using the inhaler (2). Preferably, in the closed position, the mouthpiece (10) is received into the inlet aperture (71) to protect the mouthpiece (10) when the inhaler (2) is stored.
