Valacyclovir
"This was prescribed by my Dentist.  It took another 8 months before I could try it out.  I woke up Monday morning to that little swollen hot spot on my lower lip so that was past the tingle phase.  I took  the medication as directed and upon waking on Tuesday morning it was like it had just stopped any progression.  It is now Thursday and it is almost gone.  Normally it would have been a mess of open blisters, oozing and bleeding and me knowing it would take another week to see healing start.  This medication is almost a miracle as far as I'm concerned.  I had no side effects that I know of and because it is a generic, it's not expensive.  I would recommend this to anyone."