I don't know if you've tried this method before, but I've found it makes my injections worse. I know some guys recommend this, but I'd like to know if they've actually done it or are theorizing. It seemed like a good plan, but in my case I thought the site pain was worse and lasted longer than without the b-12. This was with sustanon rather than straight prop, but same difference. I know shots vary for no apparent reason as well, but I personally shoot my b-12 and oil seperate.