It can be easy to miss, but any vial of hCG or b12 that you get from a U.S. pharmacy will have the instructions showing on the label of the vial itself. The text is tiny and short so it’s easy to miss! But it will show how much to inject, and how frequently. BUT if you need further help (and many do, you’re not alone) I have an entire set of video tutorials for injections to help you!
Here’s an example of where you would find the mixing directions – whether that’s on a plastic cover like this, or if the vial just comes by itself it would be printed in the same general area.