I got this product a few days ago and tried it, and I have to say I am very disappointed. First of all, my hair, which is an ash blonde, turned brassy yellow when I started to blow dry after using the treatment. The shampoo stung my scalp. I ended up washing the whole thing out right away after blow drying the treatment--not only did it turn the color, but the results I got were not even close to what I would get from a salon blow dry. I really do think the company is out there having its people post online to build buzz. I am disgusted with them.
ETA: I have never posted on this site before and only found it because I googled "liquid keratin" and "darker" to see if anyone had the same color-darkening reaction I did. I hope you won't let the fact that I'm new keep you from thinking twice--or three--or a hundred times about using this product.