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 Best Vitamin B12 Injection Sites: Where to Inject B12 PA Relief VENTROGLUTEAL IM INJECTION SITE The **safest intramuscular injection site**, located away from the sciatic nerve. Preferred for adults and children (>7 months) due to thick muscle mass, minimal fat layer, and B12 injections training course 300 One day course perscriber set up for prescriptions with our nurse insurance referral learning how to take blood pressures included each injection would cost you around