B12 Injection: Uses, How to Take It & Side Effects Tua Sade Vitamin B12 Injections Vie Aesthetics How to self inject intramuscular vitamin B12 Overview Guy's and St Thomas' NHS Foundation Trust NEW TREATMENT ALERT A vitamin B12 injection helps treat or prevent deficiency by delivering the vitamin directly into the bloodstream. It's often used for people with absorption issues and is usually safe How to draw up B12 (labeled as Methylcobalamin) Injections Transformations Weight Loss