Vastus Lateralis Intramuscular Injection Everything You Need To Know Dr. Nabil Ebraheim B12 Injections at Home Safety Guide for Self Administration Infusion For Health 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 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