injection

Hello everyone, Following a consultation with Dr Bansal (UK immunologist) I have finally got round to the B12 injection part of his advice. I seem to recall the Dr. Telling me to inject into the belly fat, however I have just found a YouTube video which seems to suggest the upper arm area to...

What i would like to know is that online there are people who inject themselves without the aid of the nurse, what i notice is that every single example i find online of people doing this are using a tube instrument to feed the globulins into themselves. Is the tube a necessary thing? why not...