Is this the right size needle for im injections? : r B12_Deficiency Expanded needle and syringe guide Union Medico 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 What is the recommended needle size and gauge for intramuscular (IM) injections? Syringe and Needle Selection Vaccine Practice for Health Professionals: 1st Canadian Edition Types of injections explained Intramuscular (IM) Inserted at 90 to deliver medication deep into the muscle, allowing relatively fast absorption due to rich blood supply. Subcutaneous (SC) Inserted at about 45