It depends on the skin foundation. If the skin is basically healthy and has not been rejuvenated, you can try it. As for the rebound blackening, it is based on whether the conditions mentioned above are met, that is to say, if the skin has experienced improper beauty such as repeated whitening, the skin with thin keratin, damaged skin and exposed red blood is also a flash in the pan, and the rebound blackening is inevitable. Even if the skin is basically healthy, there is no guarantee that it will not rebound and turn black, because the existence of melanocytes will not disappear, just depending on how people lighten it. Even if it becomes shallow and light, long-term maintenance and sun protection are also important factors to determine the rebound speed.