You have to get a prescription or RX from a doctor. For us, we have good insurance, it's $20 for a set of 2 shots. Also, we typically have to buy 2, one for the school to have and one for us to have.
Last week, we were at a mexican resturant, where we asked for no cheese/queso on taco. First one comes out, cheese on it, second one comes out, cheese on the bottom of the tortila. I went into the kitchen and told them, if he eats cheese, he dies. The third one was delivered by the chef and was clear.