After the potion removes the spots, the local skin appears to be anti-black, mostly due to hyperpigmentation, you can take the following methods to alleviate the treatment: firstly, you can eat more vitamin C-rich fruits and vegetables, you can also eat vitamin C tablets as well as vitamin C capsules. Secondly, you can use vitamin E capsules to puncture and apply the liquid to the anti-black location, which can reduce the melanin residue to a certain extent. Again, try to minimize going out or make sure to protect the area of the retromolarization from ultraviolet rays when going out so as not to make the symptoms worse. Finally, if you cannot recover after a period of time, you can go to the hospital to use laser removal techniques for treatment. Once this symptom occurs, you can take the following methods to alleviate, and if the situation is not good, it is best to go to the hospital cosmetic specialties or dermatology department for treatment in a timely manner.