I was so excited to try this shampoo after so many good things I read about it. After about a couple of weeks I noticed my scalp was really itchy. After the next couple of weeks my whole head was so red and itchy I couldn't stand it. I also noticed that my entire scalp was flaking. It looked like I was snowing. I stopped using it and within a couple of days the itching, flaking and redness completely went away. I was so bummed because I color my hair red and red is so hard to keep from fading. Kenra color maintenance shampoo and conditioner was the best I have ever used to prolong my hair color. I get my hair colored every 6 weeks. I hardly had any fading so I actually prolonged my visit another couple of weeks before getting it colored again. I had to stop using this product because the itching and flaking was unbearable. I gave it a 10 for effectiveness because it really works for color treated hair to stop fading, but had to give it an overall 7 because it caused itching and redness on my scalp.