Subcutaneous Injection Sites and Instructions for Safe Self Administration B 12 (Methylcobalamin) Therapy MedClub by Dr Jenn Instruction Guide for Intramuscular (IM) Self injection of B12 Methylcobalamin 1mg 5mg How to Give a B12 Injection: Step By Step Instructions Figure. Subcutaneous injection into the deltoid area The Australian Immunisation Handbook Subcutaneous (SC) and Intramuscular (IM) Injections Must Knows for Subcutaneous administration: Pinch skin with non dominant hand and hold syringe with dominant hand Always inject: 2 inches away from umbilicus (for abdomen) 3 inches