Originally Posted by The Baron
Shoulder? You might try a 25ga pin but delt shots always hurt a bit. Why not inject into your glutes?
I don't think you got it about the syringe. When you first get the pin in deep into the muscle, you are supposed to draw back on the plunger until you see vaccuum bubbles form in the barrel. Hold for a few seconds to see if any blood appears in the barrel. If not, you release the plunger and then slowly push the plunger in to inject.
Obviously, then, aspirating, which is basically taking a suction from within the injection site, will suck up traces of lymphatic fluid and cellular matter, as well as minute traces of blood too small to see. So if you inject half of the contents of the rig, roughly half of any microscopic debris is left in the syringe. NOT GOOD. You don't want to inject that, two days later! For multiple site injections in one sitting, no big deal. For storing until next shot day, it is a big deal and a violation of normal, standard, safe injection protocol. Please don't do that! You are increasing your risk of an abscess. Almost invariably an abscess will force you to go see a doc or even the emergency room to have it treated. They don't just "go away". The immune system is not equipped to get into an actual abscess and defeat it as it can an ordinary infection, because there is no significant blood or lymphatic circulation within it. You can store s pre-loaded syringe for a few days, no biggie. But you MUST NOT inject half of what is in a syringe, and save the remainder to inject two days later!