My cold sore isn't going away - it's been nearly 3 weeks and i'm on valtrex right now. new blisters form after scab comes off every time. what to do?

Herpes labialis is : Typically a self limited disease and the rash lasts about 5 days. Topical therapy with over the counter creams Abreva and Viroxyn have been shown to shorten the duration of the outbreak by about a day. Valtrex needs to be taken as soon as symptoms are felt to work effectively. I suggest being checked by your doctor to see if there is a superinfection with bacteria or something else going on.