cold sores
"I find that Zirvirax doesn't prevent the coldsore from appearing (even if applied at the tingly stage).  But what I do find is that once the coldsore appears it's very small compared to not using it.  I supplement the treatment with Lysine tablets and it keeps the blister/scab very small (about 2mm in diameter as opposed to 5-6mm) and is usually gone within two to three days rather than 1-1.5 weeks."