The method of drinking a glass of lemon water every day to whiten is not reliable. Vitamin C has a certain auxiliary effect on whitening, although lemon contains vitamin C, but each 100 grams of fresh lemon contains only about 22 mg of vitamin C, which is at a medium level in the fruit, and the amount of vitamin C after dissolving in water will be even lower, so the effect of trying to whiten by drinking lemon water every day is not obvious, or even negligible. In addition, the vitamin C intake into the body is mainly absorbed into the blood in the small intestine, and then transported to the whole body with the blood, rather than to the skin. The amount of vitamin C that can eventually enter the skin will be much less, and basically can not influence the metabolism of melanin, so it is not ideal to achieve the effect of whitening by food alone. Moreover, lemon water tastes acidic, and long-term consumption may corrode teeth and affect digestive function. For people with excessive stomach acid, or gastrointestinal and pharyngeal diseases, it is not advisable to drink too much lemon water, which can easily stimulate the disease area and aggravate the symptoms. If you want to whiten your skin, you should first pay attention to sun protection to avoid accelerating the formation of melanin due to ultraviolet radiation. People who have higher requirements for skin color can also seek help from doctors at regular hospitals, such as taking drugs containing vitamin C, vitamin E or tranexamic acid for whitening treatment, or improving skin color through medical aesthetic means such as strong pulse laser, whitening injection, photorejuvenation. But all need to take the suitable treatment plan based on the doctor’s diagnosis.