Syringes are selected based on dose, accuracy and route of administration. Insulin syringes (U 40 U 100) are used for subcutaneous insulin delivery, tuberculin syringes for precise intradermal 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 B12 Shots: Vitamin B12 Injections Benefits, Uses, Risks Dr. Axe How to give insulin shots Stead Family Children's Hospital Self injecting vitamin B12. Quick and painless jabs after a B12 by Dr Caroline Palmer Medium How to Read an Insulin Syringe Affinity Whole Health