Hi Betbigfela,
I get mine in 30ml vials and inject 2-4 times a week. There are two kinds, buy the one that is spelled Methylcobalamin, not the other one.I inject into area 2-4 inches to the left or right of my belly button. There should be no pain. Use super thin insulin pins. I was not going to refill my prescription because I can't really feel it's effects. I like another product which has L-Carnitine and B12 mixed together. My wife (she had the sleeve) swears it helps her and boosts her energy so I went ahead and got some more. L-Carnitine DOES sting by the way but you can buy special formulas were it has a numbing agent to help with that FYI. Like the other poster said, go on the hardcore bodybuilding forums and they can point you in the right direction for a source. :-) Also if you for some reason do have to pay and see a doctor, put this on a list of prescription to ask for and get all your goodies once and for all, also ask for 90 day supply with numerous refills and you should be good for a year.