Interesting about the hydrogen peroxide. I had a recent cold sore flare up. Once I felt/noticed the pre-cold sore swelling on my lip, I immediately swabbed the area down with hydrogen peroxide (for lack of a better alternative). I kept up with the hydrogen peroxide for three days, applying it liberally three to five times a day and letting it air dry on my lip. As a result, a potentially huge eruption was minor and was basically gone within four days (it normally takes two weeks for my cold sores to disappear). I was also taking EmergenC two or three times a day, which I'm sure also helped. Anyway, this is the most effective treatment for cold sores I've yet stumbled upon.