Yes Carmex lip balm that's medicated can help protect and heal a cold sore.
The Carmex lip balm will also help to moisturize your dry cracked lips if you have dry cracked lips.
Another way to get rid of cold sores is to apply some baby orajel to the cold sore. The baby orajel helps to numb the cold sore so you won't feel pain while eating or drinking anything and will also get rid of the cold sore in 1 to 2 days.
You can use the regular orajel if you want or other cold sore medicine but the baby orajel has a better taste to it so it's what I use to get rid of my cold sores and it really works.