Not all shots are the same here's a guide Injections are a fast, effective way to deliver medications, nutrients, and vaccines directly into the bodybut not all injections are the How to self inject intramuscular vitamin B12 Overview Guy's and St Thomas' NHS Foundation Trust B12 Injections for Energy: Benefits and How It Works AZ IV Medics 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)