Nioxin System 4 is formulated for fine, chemically enhanced hair - noticeably thinning.   I noticed about a year ago that I was thinning on top.  I have always had thin hair, but had a lot of it ... now, it is thin and not so much hair.   I have also always colored or bleached my hair.   So, I started using this shampoo and the system that goes with it and have noticed a considerable difference.   This product is designed to create and maintain optimum scalp environment.  The scalp must be treated properly to maintain a healthy scalp.  Like facial skin, the scalp is susceptible to...