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 Best Vitamin B12 Injection Sites: Where to Inject B12 PA Relief B 12 (Methylcobalamin) Therapy MedClub by Dr Jenn Figure. Subcutaneous injection into the deltoid area The Australian Immunisation Handbook CYANOCOBALAMIN INJECTION, USP 30000 mcg 30 mL (1000 mcg mL) 30 mL VIAL Instruction Guide for Intramuscular (IM) Self injection of B12 Methylcobalamin 1mg 5mg