Do not inject directly into a wrist or any location of pain. B12 works within the bloodstream. Inject B12 into the muscle of the upper arm or into a thigh. It will be absorbed into the bloodstream and from there work its magic.
I do not know the mechanics of action.
I do know that oral B12 requires intrinsic factor, located within the stomach, to be absorbed. As we grow older, intrinsic factor becomes less or non-existent. That is why many, like me, must inject it.
I am not a physician. I am not a medical authority. I am only sharing what I do for me. Individuals are responsible for researching and gaining their own knowledge.
at the direction of a holistic dr I was seeing, they recommended the injection into the shin