What is the best route for administering vitamin B12: intramuscular injection or subcutaneous injection? 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 body but not all injections are the same. How to self inject intramuscular vitamin B12 Overview Guy's and St Thomas' NHS Foundation Trust Learn how to administer your own SubQ (subcutaneous) injections at home with confidence. Our step by step guide covers everything you need to know, from preparing your supplies to safely injecting the medication. Our B 12 (Methylcobalamin) Therapy MedClub by Dr Jenn