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 Frontiers Appropriate intradeltoid muscle needle penetration depth in vaccine administration: an MRI study in Thailand Instruction Guide for Intramuscular (IM) Self injection of B12 Methylcobalamin 1mg 5mg How to Give Yourself a B12 Injection ThinWorks