Types of Injections, Same Needle Different Depths IV, IM, SC, and ID look similar but act very differently inside the body. This visual shows where each injection goes, how deep it travels, Efficacy of different routes of vitamin B12 supplementation for the treatment of patients with vitamin B12 deficiency: A systematic review and network meta analysis Irish Journal of Medical Science (1971 ) 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 Vitamin B12 Injections: What You Need To Know