I had very good results with L-lysine supplements (at the dosages used in herpes studies). 2000 - 3000 mg a day, divided into 2 doses. There's research to suggest that high lysine vs arginine stops viral replication (with herpes virus).
I did have to continue taking it for nearly 6 months and taper off. 1st time I stopped suddenly and the peeling returned with a vengence. Second time I gradually cut back, added a "stress formula" B-vitamin supplement, and my lips have been completely normal. Haven't taken lysine since March or April. Still take the Stresstabs a few times a week...
I don't know if anyone's tried Valtrex or something like it. I can't get a doctor to get on board with the viral hypothesis, but I think it has some merit.