B12 Injections for Energy: Benefits and How It Works AZ IV Medics Where to Inject Vitamin B12 Types of injections explained! Understanding the angles: intramuscular (im) : injects deep into the muscle at 90. subcutaneous (sc) : goes under the skin at 45. intravenous (iv) : Subcutaneous vs intramuscular whats the difference? #vitamintherapy #theb12store #injection B12 Injection sites + How to use B12 Shots Safely