It does exactly what it says! From dyed black (a year ago), it turned them back to their natural color with the first application.
With the second application a week later, it lightened them even more, and I should note that it works on natural uncolored hair as well; it lightened mine by 1-2 shades too.
It leaves a hint of coppery-ginger tone, very cute.
I left the product on for 40 minutes instead of the 20 recommended in the instructions because I have thick hair in very good condition; if you are not sure about your hair, it’s better to follow the suggested time.
In the second application a week later, I wrapped my hair in plastic wrap but didn’t heat it with a hairdryer; I left the product on for 35 minutes, and at the end of the process, I applied a 10-volume developer to my hair.
Important for those interested in bleaching: A week ago, we did a test at the hair salon to bleach just a strand of the dyed black to see how it would go. It lightened to a copper tone. Now that I applied the product, that strand has become completely blonde.
Since many users write that the hair color darkens as the days go by, I will return with an update.
Update: In the first application, it started to darken a bit until it reached the natural color. In the second application, which lightened it even more, the shade did not darken at all.
(If I do a third application, it will make my hair naturally brown-copper!)
It didn’t damage my hair, but I generally always take care of it; I keep applying oils, etc.
It is just what you need for decoloration or preparation of the hair to lighten better for bleaching.