That happened to me too, and when I took periodic breaks from it, that seemed to help. (Kind of like my head got used to it and was ignoring it.) I agree, you should stay on nizoral, of course. But in my case, I was overusing it -- like 5-7 times per week. Once I cut back to 3-ish per week, it helped its effectiveness. I also rotate in T-Gel as a substitute every now and again, which seems to help. (For instance, 2x nizoral plus 1x T-Gel in a week occasionally; or a whole week with T-Gel, then back to nizoral.) You'll probably have to play around with rotating shampoos a bit. Everyone seems to react slightly differently.