Eflornithine
"I had been using this cream for several years, and it helped lengthen the time between hair removal. Then, it stopped working. I'm not sure if I built up a tolerance to it, but it was like I wasn't using it at all. So, I took a break for about 10 months and just started using it again. I'm hoping it will start working again. If not, I don't know what I'm going to do. :("