Abreva
"I had a cold sore on my lip and as soon as it went away two others popped up. They were so bad and I was so miserable so I finally went out and got abreva. I'm on day six of using the medicine and my cold sore is already gone!  It would've went away so much sooner if I hadn't waited so long to get the medicine, it's expensive but it's definitely worth the price!  I'd recommend abreva to anyone who has a cold sore you will not regret it."