The trade-off is larger injection volumes at standard doses: a 2.5mg dose requires 75 units, and a 5mg dose requires 150 units (two syringe draws)
However, as with any compound, its vital to understand how it behaves within the body
Epithelial defects completely healed within three or four days (2 g or 2 ng regimens, respectively), aqueous cells were not present after four or five days after injury
Philp et al
That claim rests largely on a single, genuinely interesting laboratory study: Pyo et al
Here are the best vitamin B12 injection sites for each method: Subcutaneous B12 injection sites Usually, the best places to give yourself a B12 shot subcutaneously are the abdomen, thigh, and upper arm, as you can see in this illustration: Although not shown above, the buttock is another good site for B12 shots