Review (4/5): Potently effective
I have used this product twice. I left the product in for 15 minutes the first time, which gave my hair - initially - a sort of lavender glow. I should note that 15 min is the maximum time they recommend, but I was feeling brave. The lavender faded away, so no worries. At least the yellowish tint was gone! The second time I used it I left it on for 10 minutes, much better. I like this product. It is potently effective, so be prepared!