Does anyone have any experience with this?
Most Helpful Girl
They are contagious but only to some people. A part of the population is imune to canker sores but I wouldn't play russian roulett with it. You could get these sort of plasters from the pharmacy they will both heal it faster and make it less likely to transfer.
PS: I know this wasn't you question: But in rear cases it can transfer from lips to genitals during oral sex. So be careful1