I use a prescription called Acyclovir for my cold sores. I do not take it all the time only as needed. Whenever I start to feel like I am getting a cold sore I take it and it cuts the healing process time way down and also the sores don't seem to be as bad either. I really like the stuff, it does not seem to have any bad side effects. I just always keep it on hand. And sometimes if I know I am not going to get enough sleep or am really stressed I will start taking it.