Just wondering if I'm on the same track here, but test prop is an oil....yes? and b12 is water....yes? Or are we talking about suspension? It is not a real good idea to mix oil and water together as in they don't mix. Unless b12 is in oil which I've never seen. I mix my prop with a little deca or cyp, this tends to calm it down a bit. But after a while you will get used to the injections. I mainly just hit up the prop on it's own, iit's not so bad after a while. Now suspension is another story, this shit just plain hurts.