b12 im injection needle size for a Injection: A Simple Guide is b12 injection intramuscular or
Description
After this period, injections can be administered once per month, which this frequency is enough to reverse the signs of vitamin B12 deficiency
If vitamin B12 deficiency is not treated with a vitamin B12 supplement, then anemia, intestinal problems, and irreversible nerve damage may occur

this compound remains investigational

Overall, the lasting time of vitamin B12 shots would vary depending on the requirement and purpose
