cold sores
"Let me start by saying (1) I'm compulsive in terms of researching everything (2) I get the worst cold sores known to man and my lip blows up about 4x.  With all that said, Valtrex is the real deal.  A cold sore is a Virus (as I'm sure you all know by now) that injects its own foreign DNA into your cells which in turn mutates them which is why you get a cold sore - the way Valtrex works is by blocking the viruses ability to inject its own DNA into your cells.  So, if you take Valtrex at the FIRST sign of "tingling", you may never develop a cold sore. I on the other hand developed a sore this past Tuesday (took Valtrex too late), have been taking Valtrex every 12 hours since, and it is now Friday, my lip is fully deflated and scabbed."