Instruction Guide for Intramuscular (IM) Self injection of B12 Methylcobalamin 1mg 5mg How to Give a B12 Injection: Step By Step Instructions Sites of Administration of Subcutaneous injection Figure. Anatomical markers used to identify the vastus lateralis injection site on the anterolateral thigh The Australian Immunisation Handbook Safe IM Injection Site Intramuscular injection should always be given in the **upper outer quadrant of the gluteal region** to prevent sciatic nerve injury. Key nursing points: Upper outer quadrant =