Objective: How should I use a sumatriptan injector?

Which of the following solutions is more sound in terms of naive physics reasoning?

OPTIONS:
- Load the sumatriptan into the injector pen. Hold it firmly to your arm and press the button. Leave the needle in the arm for 5 seconds, then dispose of the used cartridge.
- Load the sumatriptan into the injector pen. Hold it just above your arm and press the button. Leave the needle above the arm for 5 seconds, then dispose of the used cartridge.
Load the sumatriptan into the injector pen. Hold it firmly to your arm and press the button. Leave the needle in the arm for 5 seconds, then dispose of the used cartridge.