Subcutaneous Injection: What It Is and How to Give One How to Give Yourself an Intramuscular Injection 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 B12 vitamin Store A Manual for you all: What are B12 injections? Where to give B12 injections shots? How to give B12 injections?