I have seen Qingming, and the weather is getting hotter every day. Sunscreen whitening has been put on the agenda by many girls. But how can we achieve the ideal sunscreen whitening effect? The following is my personal opinion. It's better to take precautions than to mend them. Taking appropriate measures to prevent skin blackening and spots will get twice the result with half the effort. Especially after the age of 25, personal metabolism slows down and the skin begins to decline. At this time, the damage of external factors such as ultraviolet rays to the skin is irreversible, and it is difficult to restore the original state through self-repair. To achieve the ideal sunscreen and whitening effect, we should mainly do the following: 1. UV protection is the direct culprit of melanin precipitation, skin blackening, dark spots and wrinkles, so the simplest and most basic way to prevent skin blackening and spots is to minimize ultraviolet radiation. Try to do the following: 1 to avoid exposure. Try to avoid 10, where the sun is strongest, from morning to 3: 00 pm, and places such as seaside, beach and mountain top. 2. Take an umbrella, hat, sunglasses and long-sleeved clothes made of cotton and linen. But these can only block some ultraviolet rays, and umbrellas and sun hats can't stop ultraviolet rays reflected from the ground. 3. Use sunscreen correctly. Many people think that the use of sunscreen is ineffective, mainly because of improper use. Pay attention to the following points when using sunscreen correctly: (1) Choose sunscreen with different SPF values according to the occasion. The selected sunscreen should not only have the function of preventing UVB (sunburn), but also have the function of preventing UVA (aging and wrinkles). The higher the sun protection value, the greater the burden on the skin, and the more likely it is to cause skin allergies. Therefore, the choice of sunscreen is not that the larger the SPF, the better. And you'd better wash the sunscreen in time when you get home. Sunscreens with SPF of 10- 15 and SP+ can be selected for daily life, those with SPF of 15-20 and SP++ for shopping, those with SPF of 20-30 and sp++ for traveling, and those with SPF of 30 or above for swimming and sunbathing. (2) The damage of ultraviolet rays to the skin will exist even in winter, indoors and cloudy days. On cloudy days or in the shade of trees, the intensity of ultraviolet rays will only decrease by about 30%. Therefore, we should insist on using sunscreen all year round, rain or shine. (3) It takes some time for sunscreen to absorb and take effect, so it should be applied 20-30 minutes before going out. (4) SPF values cannot be accumulated and cannot be used before makeup. When using sunscreen, you need to remove makeup before applying it. 5], sunscreen use needs to reach a certain thickness to be effective. Too thin can not achieve the desired effect, too thick will cause a burden on the skin. Generally, the application amount is 2mg per square centimeter, 2-2.5g for a pair of arms, and1-1.5g for a face. 4. The damage of sunlight is cumulative. Most melanin in adults is caused by exposure to sunlight in childhood. It's never too early to start whitening, freckle removing and sun protection from children. A six-month-old baby can't take a beach bath. Children should wear T-shirts and sunscreen before they are 7 years old. /kloc-before the age of 0/8, it is the key to sun protection. 5, timely repair after tanning is a state of scald, for the skin that has been exposed to the sun, it should be repaired in time. Cold compress with cold water or ice water, or ultrasonic cold spray for 20 minutes can reduce the activity of melanin and free radicals, replenish water and minimize the damage of ultraviolet rays. You can also use after-sun repair products containing aloe, mint and other ingredients for repair. Second, keep a happy spirit, live a regular life and exercise properly. Mental interference can produce abnormal hormone secretion. Nervousness, anxiety, bad temper, insomnia and fatigue will all aggravate the generation and expansion of black spots. Hormone imbalance leads to uneven molecular distribution of melanocytes. Proper exercise can prevent diseases, accelerate blood circulation, regulate qi and blood and endocrine, and has certain anti-plaque effect. Third, balance nutrition and develop correct eating habits. Insufficient nutrition intake can easily lead to nutritional deficiency, which will lead to gastrointestinal dysfunction and poor liver function, making black spots more serious. Irritating foods, especially coffee, cola, strong tea, tobacco and alcohol, will make melanin molecules float on the skin surface, forming and expanding black spots. There are more senile plaques in the south than in the north, which is not unrelated to their habit of drinking strong tea. On the contrary, Vc and VB3 can effectively inhibit the formation of melanin, reduce the transmission of melanin to keratinocytes, promote the shedding of melanocytes and promote the synthesis of epidermal proteins, thus enhancing the self-defense ability of skin. Therefore, we should pay attention to eating more fruits and vegetables rich in Vc and VB3 in diet, and avoid eating sensitive foods such as oranges, lemons, carrots, celery and parsley before exposure to the sun. Fourth, avoid using inferior cosmetics and some drugs. Some cosmetics contain too much chemical pigments and mineral oil, which are particularly sensitive to absorbing ultraviolet rays, thus stimulating the proliferation of melanocytes. There are also some whitening products that unilaterally pursue temporary whitening effect, and the contents of mercury and lead are seriously exceeding the standard. Long-term use will also cause cosmetics poisoning and form black spots. In addition, long-term oral contraceptives, or allergies to other drugs, can also lead to the formation of black spots.