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) How Quickly Does B12 Shot Work? Duration of Benefits B12 Shots at Home: How, Where & How Often to Inject Yourself AZ IV Medics Needle Injection Techniques Every Nurse Should Know!, Whether youre prepping for your NCLEX or brushing up on your skills, heres a quick breakdown of the most common injection routes youll