Valtrex and acyclovir are the same med basically... so if one cause hair loss, the other will too. Tthis has happened to me. I am devastated. I have to decide between a constant outbreak or massive hair loss. I opted for the outbreak... because as a hairstylist, my hair is important to me. I already feel so depressed about the diagnosis, now the hair loss is awful. My doc keeps telling me she's never heard of this happening, which is very frustrating as clearly it happens to lots of people!! Have you found anything that helps??