I haven't had a yeast infection in years ,but I got one when I started riding long distances. Not sure if this is the right answer ,but I bought some Monistat cream ,and used it the night before a long ride...it seems to work ,but I'm not sure if that is the right thing to do...Oh, I also use the Butt'r ,and I haven't had a problem. I'm sure someone else will have a different answer. Good luck