There is a theoretical case for using both in certain patients, targeting different physiological mechanisms simultaneously, though this approach is under evaluation and not yet standard of care
Follow-up labs help show whether the injection schedule is working
I have trouble reaching my upper arm, and when I used to get the Dr to do it in the arm I would have pain for hours that radiated down my arm
As researchers from Cornell University Medicine stated, Management requires correctly diagnosing cobalamin deficiency, reversing it, defining its underlying causes, preventing relapse, managing the underlying disorder and its complications, and educating the patient. Do You Need B12 Injections
The intramuscular route ensures consistent, reliable delivery of B12, independent of gastrointestinal absorption