A cartridge for containing and dispensing a medicament, the cartridge including a cartridge body having an interior cavity therein, a stopper movably disposed within the interior cavity, and a septum disposed at an opposite end of the interior cavity from the stopper, for containing the medicament within the interior cavity. The cartridge also includes a connection thread integrally formed as a unitary construction of the cartridge body, the thread being disposed at a first end of the cartridge body for connecting a pen needle directly to the cartridge body to pierce the septum and provide communication between the medicament and a patient end of the pen needle.