Nope, my pharmacy has to order it so it takes a day and I did it on a friday when I was already out and they were closed on the weekend (its a pharmacy on a college campus). Anyway I was fine for four days. I did break a tablet in half the first couple days nobody told me to per se just felt like the right thing to do. So to answer the question I had no adverse affects from being off it for four days and going right back on it. Hope that helps good luck