cold sores
"At the first sign of a cold sore, I have taken 2 g of valacyclovir (once at first sign then again 12 hours later) and managed to prevent them from forming. As soon as I notice the tingle, I take it. Sometimes I get a little bit of a stomachache from it, but eating a moderate amount with it seems to prevent that. The mild stomachache is much more tolerable than cold sores though. Overall, I have been very happy with valacyclovir."