Subcutaneous Injection Sites: Thigh, Abdomen, and Arm Ultrassist B12 Injection sites + How to use B12 Shots Safely How to Give Yourself Intramuscular (IM) Injections Patients & Families UW Health Hiya. I have a question. Is a B12 injection basically a dose of iron? Types of Injection Injection is a method of administering medication directly into the body using a needle and syringe. It allows fast and effective absorption of medicines. Intradermal (ID)