Ick. I hated them!! But of course, I was using a doctor that didn't understand that I couldn't use even the injected form of cyano type of B-12. An hour after every shot, I had to lay down for 2 hours because my exhaustion was overwhelming. So 3 hours out of each day that I had to have a shot (3 times a week) was lost due to having a B-12 shot!! I ended up just taking a double dose of the under the tongue type of methyl B-12 for a few months and I did better.
If this happens to you - insist on the methyl type as this is the type the body doesn't have to convert.
www.globalhealingcenter.com/natural-health/four-types-vitamin-b12/I believe that mkg and ml are the same amount expressed in different weights is all.