Best Vitamin B12 Injection Site: Administering B12 Shots 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 Intramuscular injection is shown at 90 because the goal is to reach the muscle, the deepest layer in this comparison. That route is chosen when medication needs reliable absorption through the muscle's Common IM Injection Sites Deltoid (Upper Arm) Location: About 23 finger widths below the acromion process (shoulder bone). Best for: Vaccines and small volume injections (1 mL). Notes: Easy to access but limited Where Does B12 Injection Go TikTok