Where is a vitamin B12 (B12) injection typically administered? Where Does B12 Injection Go TikTok Luminous B12 Injections What is a B12 injection A B12 injection is a form of supplementation where vitamin B12 is administered directly into the muscle or under the skin, bypassing Instruction Guide for Intramuscular (IM) Self injection of B12 Methylcobalamin 1mg 5mg Sublingual B12 vs Injection WhyNotNatural Instruction Guide for Intramuscular (IM) Self injection of B12 Methylcobalamin 1mg 5mg