"The Bionic Man"
he claims that shooting into a vein is bad for you. It could affect your heart muscle. You could get a stroke. But even worse, if the gear would be in your bloodstream it attaches itself somewhere in your body, in the liver, kidneys, everywhere. Furthermore it can clogs together. So then you have more then 1 molecule (like Winny). So many molecules can make one big thing. Like a time bomb in your body. Then later on this can get free anytime and then the many "together attached molecules" travel through your bloodstream. And who knowes what this will do to your heart. Maybe a heart attack. Anyway, it is not healthy.
For the air bubbles: get rid of those. Even if you need at least 2, 3 or has some claim 10 cc's to kill yourself; don't be the one who managed to commit suicide because you only needed 1 cc of air to do so.