A dry powder inhaler, including a housing having an airflow path leading from an inlet, past a powder release location, to a mouthpiece; a drive spool engaged with a capstan adjacent to the powder release location; a spring biasing a ratchet into engagement with the drive spool; and a breath trigger in the airflow path. The breath trigger is moveable from a first position, wherein the breath trigger holds the ratchet, to a second position, wherein the breath trigger releases the ratchet to allow the ratchet to turn the drive spool.