How to Give B12 Injections at Home to Yourself PA Relief Compounded Methylcobalamin (Vitamin B12) Injection, 5mg mL 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 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 B!2 Inject Kit: Package Insert Prescribing Information How to Give a B12 Injection: Step By Step Instructions