A medicine reservoir (10) is provided for use with a drug delivery device (50). The medicine reservoir (10) is arranged for comprising a drug (13) and comprises a dispensing hole (15) for dispensing the drug (13) into an environment of the drug delivery device (50). The medicine reservoir (10) further comprises a deformable plug (14) which plug (14) is removable by pressure caused by a dispensing action of the drug delivery device (50).