B 12 (Methylcobalamin) Therapy MedClub by Dr Jenn Types of injections explained! Understanding the angles: intramuscular (im) : injects deep into the muscle at 90. subcutaneous (sc) : goes under the skin at 45. intravenous (iv) : Vitamin for Cattle , Sheep, Swine , Horses, Dogs & Cats B 12 1000mcg Injectable 500cc [Anemia Treatment] On Sale EntirelyPets Rx 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 Best Vitamin B12 Injection Site: Administering B12 Shots