Fractional laser, also called carbon dioxide fractional laser, is more effective on acne pits. The fractional CO2 laser is irradiated once a month, 4-5 times in a row, to produce visible results. The special stimulation acts on the surface of the depressed acne pits, causing the fibroblasts inside to increase their proliferation rate and undergo secondary proliferation, which gradually flattens the depressed area and achieves the treatment effect. The laser is irritating to the skin, and after each treatment, there may be localized fractional burn marks, as well as diffuse flushing and burning. It is necessary to use cold compresses with ice packs after the use of CO2 fractional laser, and you can choose to use restorative masks, which can avoid skin irritation and accelerate local recovery.