How to Self Administer Subcutaneous & Intramuscular Injections Dr. prescribed B12 injections. Pharmacy only gave me vials. Where do you get your needles and syringes? What size?? Where do I inject? : r B12_Deficiency 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 Choosing the Right Needle and Syringe for B12 Injections: A Complete Guide Insulin syringes Understanding the Differences: Insulin Syringes vs. Regular Syringes Do B12 Injections Hurt? Painful Shots No More PA Relief