How to inject B-12?

I've been injecting B-12 for several months, as taught by my doctor's office. They showed me how to inject subcutaneously. However, I have heard that B-12 should be injected intramuscularly, and I'm concerned that I'm not getting the best nutrition. I did have a blood test 3 months after starting the injections, but I had just injected the night before so naturally my B-12 was high. Does anybody here inject? And which way do you do it? Thanks, Cris [email protected]

I am a nurse and I have seen B-12 ordered both subcutaneously and intramuscularly. Caryl