Lets do my first B12 injection together This is something Ive been nervous about for a long time, but today I finally did itand it honestly wasnt bad at all. I used the Union Medico needle guide Injection Techniques Step by Step Guide 1. Intramuscular Injection (IM) 90 Angle Needle Position: Perpendicular to the skin (90 angle) Target Site: Muscle layer Common Sites: Deltoid, Vastus Lateralis, Best Vitamin B12 Injection Sites: Where to Inject B12 PA Relief How to Self Inject Vitamin B12 at Home The Sanctuary Wellness Institute