Lysine
"When I get stressed, drink lots of alcohol or even go in the sun I'm almost guaranteed a cold sore. Unlike most people I don't feel an itch it just pops out of nowhere. I take about 5000-8000mg the first time I notice it and it definitely reduces the size! Then I decrease the dosage slowly. I find it does make them go away faster and the nasty blister stage isn't so nasty anymore. Maybe if I could catch it in time I wouldn't have them because lysine works!!"