1 ml b12 injection Compounded Methylcobalamin (Vitamin B12) Injection, 5mg/mL made form of vitamin B12 Buy Vitamin B12 Injections, 2000mcg
Description
Clin Nutr

So, a 1 mg dose of B12 is the same as 1000 mcg
Because of this origin, it is studied as a potential communicator between mitochondria and the rest of the cell, a role researchers refer to as retrograde mitochondrial signaling

Injecting B12 Choose an injection site
