Cold Sores
"Let me start by saying (1) I&#039;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&#039;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 &quot;tingling&quot;, 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."