Follow the storage instructions on the vial and pharmacy label
The product is likewise indicated for increased physiologic demand (pregnancy, thyrotoxicosis, chronic hemorrhage), for drug-induced depletion, and for select neurologic or hematologic disorders in which B12 plays a pivotal metabolic role
Testing confirms exactly what you need
Clinicians may monitor complete blood counts, vitamin B12 levels, methylmalonic acid, homocysteine, potassium, or other markers depending on the situation
The effects of a single B12 injection typically last one to two weeks, though this varies depending on your baseline levels, metabolism, and overall health
For that reason, compare the total contents with your injection schedule rather than judging value by vial count alone