A hypodermic injection device configured to be attached to a portable electronic device is disclosed herein. The hypodermic injection device can be an auto-injector for delivering a dose of an injectable medicament. The injection device can include a durable barrier providing a sheath over an injectable cannula to maintain sterility of an injectable cannula that delivers the medicament. The injection device can also include tamper proof features such as by requiring that deployment of the device only be possible after completing two mechanical manipulations so as to prevent accidental discharge of the injection device. By incorporating the injection device within a case for a portable electronic device, the injection device is readily available to those that rely on auto-injectors to provide emergency therapeutic treatment, and is much less likely to be forgotten or left behind by a user than a typical auto-injector.