Firstly because I have hair that pull on the red and I wanted to remove these copper highlights thinking that would be nice and brown ... no! It gave me even more red !!! It darkens a little hair but takes no shampoo! Moreover, we must put a considerable amount to cover all the hair. By cons it gives a great texture to the hair, but that was not why I bought it ... So I will not serve more and I do not advise anyone who, like me, wish a change the color of their hair ...