text: how do u get rid of cold sores and how long do they last? need help cold sores? hello, this is a herpies virus, you will never get rid of this virus, when it isnt visible physcially, it is laying dormant in your body and usually attacks cells with your immune system is low.  there is a great ointment out named ziveriax ( i think thats how you spell it), if you put that on as you feel that typical cold sore tingle, it will kill it before it erupts. i know they can be painful i used to suffer from them.  i know personally, mine last about 1-2 weeks. if you keep yoruself healthy, you shouldnt get too many of them. i havnt had one for years. good luck with it.