The patch itself is just to keep the anesthetic in place and so it doesnt go everywhere when you move around, like get on your clothes and such. The cream is called elma cream, it may be something different where you are. You should be able to just ask for it when you go to have your blood test done. Otherwise use something like toothache gel or stuff for insect bites and it should numb the spot somewhat. It takes an hour to work. As for why I put it on before I got to the office, you dont need to make an appointment for the blood test you can just go straight in. If youve ever tried using anesthetic while you are waiting for a blood test youll have endured the 'it only takes a second', 'its only a little prick' from everyone in the room. Even the pathologist today found it amusing. I was hiding my face and close to tears because I was freaking out, so dont push your luck! At least I showed up!