Valacyclovir
"I just want to say that this med has gave me my life back. I have read some of the other reviews and if you having trouble with side effects from this pill please try a different pill made from a different manufacturer. All of them are different. I hated the Mylan (122) brand.  It gave me a headache, couldn't sleep and couldn't focus. I switched to one made by teva and it has been great. No side effects at all."