A palm-controlled device is disclosed for injection of a substance into an organism. The device includes a palm-receiving surface for receiving a palm of a hand, the palm receiving surface being shaped so that the palm is substantially parallel to a surface of an injection site of the organism while operating the device. The palm receiving surface can also be shaped so that the palm is substantially perpendicular to a surface of the injection site. The device also includes an injector having at least one pre-filled syringe, the palm-receiving surface being cooperative with the injector such that when pressure is applied to the palm-receiving surface, the injector is actuated so as to inject contents of the at least one pre-filled syringe. Actuation of the injector is by gradual pressure not sudden motion. Single or multiple doses of same or different medications can be included in a single injector.