Needle Injection Techniques Every Nurse Should Know! Whether you're prepping for your NCLEX or brushing up on your skills, here's a quick breakdown of the most common injection routes you'll encounter How to Give a B12 Injection: Step By Step Instructions Methylcobalamin Injection (Vitamin B12) Empower Pharmacy 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) : B12 vitamin Store Intramuscular vs Subcutaneous Injections for vitamin B12 supplements.