One thing that has been crucial to helping deal with injecting myself with thiamine is the use of an auto injector. Not trying to advertise anything here, but without it, I would be more stressed about screwing up the injections. It's true peace of mind. I'm using the one by UnionMedico in Europe. I bought the Super Grip model, along with the correct needles. Which also brings up a different question...which needle length do people use and where do people prefer to inject themselves on their bodies? I use a 1.25 inch, 23 guage needle and switch off between thighs.
Just thought I'd pass this along for folks considering thiamine via injections. I've been doing injections for almost two years and feel that the thiamine doesn't improve my symptoms so much, but do feel that it has kept my condition from progressing, which is a bonus enough to stay with it.