Not all shots are the same here's a guide Injections are a fast, effective way to deliver medications, nutrients, and vaccines directly into the body but not all injections are the same. Types of injections explained Intramuscular (IM) Inserted at 90 to deliver medication deep into the muscle, allowing relatively fast absorption due to rich blood supply. Subcutaneous (SC) Inserted at about 45 How to self inject intramuscular vitamin B12 Overview Guy's and St Thomas' NHS Foundation Trust Cyanocobalamin (b12) Injection 2,000 mcg mL 30mL Conquer Pharma Intrav My Store 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