Please describe the most effective treatment for a cold sore?

Best RX is TIME: The lesion undergoes a series of changes and heals over 14-21 days--after which the virus goes dormant. Anti-viral drugs based on Acyclovir are available by prescription and can be taken as a preventive med. Otc meds, like abreva, have variable success rates. I often use a laser to help stop the progression of the lesion if my patient presents during the prodrome phase--see your dentist early