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 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 bodybut not all injections are the B12 Shots at Home: How, Where & How Often to Inject Yourself AZ IV Medics B12 Injection DRIP AND DIP Methylcobalamin Injection (Vitamin B12) Empower Pharmacy