B12 Shots at Home: How, Where & How Often to Inject Yourself AZ IV Medics Optimal B12 Injection Sites for Maximum Absorption and Benefits Your Health Magazine Subcutaneous Injection: What Is It and How to Give One Ro B 12 injection without syringe and needle How to self administer subcutaneous B12 injection., 1. Withdraw proper dosage from vial into an insulin syringe, 2. Clean site of injection (abdomen or other proper site), 3. Pinch the skin where you