Common IM Injection Sites Deltoid (Upper Arm) Location: About 23 finger widths below the acromion process (shoulder bone). Best for: Vaccines and small volume injections (1 mL). Notes: Easy to access but limited Goat Health How To: Injection And Drenching Hobby Farms Text Giving a Subcutaneous (Sub Q) Injection (Single Medicine) What Happens If You Inject B12 Wrong: 6 Red Flags B12 Shots at Home: How, Where & How Often to Inject Yourself AZ IV Medics B12 vitamin Store How to Perform a Subcutaneous Injection of Vitamin B12