How long it takes to see the effect of laser nevus of Ota removal depends on the severity of the nevus of Ota and the type of laser applied. Usually, after one laser treatment, there will be local bleeding, crusting and pigmentation for about 1 month, after which the effect of nevus of Ota reduction can be gradually recovered and seen. However, if the color of nevus of Ota is darker and larger in scope, the effect may not be particularly obvious after completing one treatment. In general, the effect of lighter colored nevus of Ota is more obvious after one laser treatment, and a more pink and clean tissue can be seen. For darker nevus of Ota, multiple laser treatments are needed and the effect can be seen only after the scab peels off on its own, after which the red and black lesions can be seen and then slowly fade away. The specific time depends on the patient’s condition and the course of treatment. The interval between multiple laser treatments is usually 3-6 months, and when the nevus of Ota is larger, more and deeper, usually 3-5 times are needed, but the specific situation varies from person to person. As the number of laser treatments increases, the area of the mole will become smaller and the damage of the laser to the skin will be reduced. However, pigmentation may appear in the area after each laser treatment, and the pigment will gradually fade after the scabs fall off, during which time sun protection measures should be taken. Whether the nevus of Ota is cleared or not is mainly to observe whether the fresh skin after the scab is removed is clean and whether the normal skin color is restored. If there is still a cyanotic mark, the treatment needs to be continued. If it is consistent with the surrounding skin color, the laser treatment can be stopped, but a follow-up examination is required about once in 6 months as prescribed by the doctor to evaluate the treatment effect.