A drug delivery device has a cartridge holder adapted to receive and hold a cartridge, the cartridge holder having a receiving and a holding state. The device further comprises a drive assembly with a piston rod and a drive spring, setting means allowing a user to set a dose amount to be expelled and strain the drive spring correspondingly, and user actuated release means for releasing the drive spring, wherein the drive assembly spring cannot be released to move the piston rod unless the cartridge holder is in the holding state.
