How To Give Yourself an Intramuscular Injection IV Me Now FL Vitamin B12 Injections Energy Boost The Center Medical Types of injections explained! Understanding the angles: intramuscular (im) : injects deep into the muscle at 90. subcutaneous (sc) : goes under the skin at 45. intravenous (iv) : 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 Understanding the 4 main types of injections makes medical knowledge simple and clear. Intramuscular, Subcutaneous, Intradermal & Intravenous each one plays a different role in treatment. Stay informed, stay safe!