caffeine works well if you catch it just as you feel the first tingles before an outbreak - make a paste with instant coffee and smear it on - not very attractive but it works

You need to boost your immune system.  Vit C, Zinc, Olive leaf extract, Vit E, garlic, Echinacea, the herb Astragalus (at the first sign of a sore).  My husband uses Carmex lip balm on his cold sores - only thing that works for him.  But a cream with Lemon Balm is supposed to be very good too.  Hope this helps

Cold sores...try L-Lysine! This amino acid does magic and actually prevents them from appearing on the first place.
I use the one from Bluebonnet (iHerb stuff)
Good luck!!

If you have any intrest, the paleo community I have met here in Utah introduced me into using Essential Oils as Paleo Medicine. They work very well! I used a blend of Melaleuca (for the antivirial benifets) and Lavender (for the skin irritation benifet) on my husband recently and his cold sore never even broke the surface of the skin. He was very happy about that. Also Melissa and Lemongrass work great. Research has showed adding Melissa to your daily suplement regimen will actually help keep the sores from coming back at all period. We use doTERRA out here because its of the highest and pure grade, and the only essential oil safe for internal use. Hope this helps!

I tell this to people with cold sores all the time, but never get someone who tries it.................... Solaray: Once Daily High Energy(iron free) has been a blessing for me. Normally when I am overly tired, stressed, mentally or physically stressed I will get a cold sore. But when I take that stuff twice a day I never get them. I have been up for 36hrs straight, terrible cold, broke up with girlfriend, about to be fired stressed out and still no cold sore.