Trial and error. I tried many before one worked. There presciption shampoos that work, but this works just as well.

Thank You Dale;
I just checked it out of Amazon, and will definitely be considering this product. I'll need to read more. How did you learn about this product?

I have this as well. I use T-Gel. It’s a very thick shampoo that moisturizes and medicates your scalp. It works for me.

Selsun Blue did not work for me. I'll try again...

I have itchy scalp a couple of years ago I visited my GP and was prescribed a shampoo. Which seemed to help, so I quit ordering it from the pharmacy. Recently I send an email to my GP, and he told me that the shampoo I was prescribed was the same as Selsun Blue, so I have started using it. If the results are good, I'll let you know. BTW, when I first started using the prescription shampoo it took a few washes for it to work.