While I have yet to find any success curing my cold sores, I have found one particular thing which prevents them.
It seems that certain remedies work well for one type of person but not the other, in the past I have tried Lysine, over the counter meds (they worked for a while), ice cubes, finger nail polish remover.... Ummm just about everything. Non of those worked well for me, for the past three years I have been using a licorice/peppermint root extract in gelled form. When I feel a cold sore coming on and I use this (I apply it every several hours at the onset) it never comes, I use this if I know I might get a cold sore (I'm sick or something), and I use this on my son. Unfortunetly, he doesn't know when a cold sore is coming on so it is usually already surfaced by the time I see it. However, when I put it on him the cold sore goes away very quickly and stops growing. I have noticed that over the years my cold sores are getting farther apart. I use to get them about 8 times a year and now its about 3-4.
If nothing else has worked for you, this might be the one- because nothing ever worked for me!