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 Self Inject B12 How to Inject Vitamin B12 medicalweightlosscentersofamerica.com 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) :