How to Give a B12 Injection: Step By Step Instructions How to self inject intramuscular vitamin B12 Overview Guy's and St Thomas' NHS Foundation Trust Hi Dr. Tony here! If you give yourself injectionstestosterone, estrogen, insulin, peptides, or B12these are 3 of my favorite tips to make them almost painless. Tip 1: Insert the needle quickly, then How to Give a Buttock Injection Intramuscular Injection Technique vitamin b12 injection How to Self Administer Subcutaneous & Intramuscular Injections How to draw up B12 injections