Efficacy After whitening, the skin will be particularly fragile, and there is no whitening product that does not rebound. It is recommended that you use an isolation sunscreen or a straight umbrella to protect your skin before going out, and you must keep up with the hydration. In fact, many people don't understand. Human skin cells are like riverbeds, and capillaries are like rivers that shuttle between riverbeds. Blood is like river water, and melanocytes are like sand. When the water flow in the river decreases, the flow speed will slow down, and the sand in the river is more likely to deposit on the skin. The water in the blood will decrease and the blood flow rate will slow down. It is also easier for pigment cells to deposit on the skin surface. Some of the moisture in the skin comes from drinking water, and some comes directly from skin care products. It can maintain the whitening effect to the maximum extent.