Injection Syringe: Different Types Engiomed 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 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 Needle Sizes Explained: Choosing the Right Gauge for Different Injections