A portable handheld fluid-medicine-injection device for individual users, has a medicine vial has a substantially rectangular cross section that reduces a thickness profile of the device and a dispense mechanism coupled with the vial, the dispense mechanism has an inject push rod inside a threaded cylinder that reduces a length profile of the device. The device has a needle with a needle mount/dismount mechanism coupled with the medicine vial and a needle storage mechanism that stores the needle when not in use and replenishes the needle for reuse.