The appearance of melanin is related to ultraviolet radiation and chemical stimulation or to one’s own hormone level. It is mainly due to the active proliferation of melanocytes in the basal layer of the skin, or an increase in the number of melanocytes, which causes hyperpigmentation of the skin in the patient’s appearance. The specific time to fade depends on the type of pigmentation, usually 1-2 months, some 6 months to 1 year, and some cannot fade on their own. The epidermal turnover time of the skin is 28 days, so lighter dark red pigmentation can be metabolized after at least 1-2 months. However, for longer, darker brown pigmentation, it takes 3-6 months for the skin to metabolize before fading. For black hyperpigmentation, it is difficult to subside on its own through skin metabolism and must be removed with oral or introduced tranexamic acid, topical hydroquinone cream and laser combination. There are certain treatments for hyperpigmentation, but there is no better cure. Once the patient has melanosis, it is important to avoid light as much as possible and do a good job of sun protection, including going out under a sunshade, wearing a hat, and wearing sunscreen.