L-Lysine will work. Someone here gave the dosage. It can't hurt you to try it. Most MDs do not know how to treat with vitamins, minerals and/or amino acids. It is a real shame. If I know something natural that will help me, I usually ask the MD, "Will this hurt me?" Having something like shingles for a long period of time tells me there is something wrong/missing in the body. Let's correct that, if possible.
L-Lysine also works for fever blisters, mono-nucleosis, and any herpes-type infection.