can you give b12 injection in deltoid Administering a Intramuscular : 5 Steps How to Administer an Intramuscular
Description
You can find more scientific research on B12's role from sources like the National Institutes of Health

Your personal injection schedule will be custom based on your initial B12 levels, the underlying cause of your deficiency, how well you respond to treatment, and ongoing blood test results

The addition of GIP receptor activation appears to reduce nausea while enhancing metabolic effects

& Tohda, C