"If you ignore sun protection, you are accelerating skin aging and wasting money on various plastic surgery." Dr Adam Gay, a dermatologist in new york and a professional medical consultant of Kiehl's, said. A. It has a strong and lasting sunscreen effect (corresponding to SLOGAN's "whitening double effect", and at the same time, it isolates UVA and UVB to help the skin maintain a fair health and prevent aging)
B. In addition to strong and lasting sunscreen effect, it also has the characteristics of "4 exemptions": (corresponding to the advertising slogan "4 exemptions without burden")
Colorless: no pigment, colorless emulsion formula, will not make facial skin shiny and white residue.
No spices: no spices, mild in nature.
Oil-free: not greasy, will not block pores, will not cause acne.
No allergy: tested by dermatologists, it is suitable for sensitive skin and will not cause skin sensitivity.
C. Sun protection can also moisturize the skin and prevent skin aging.
D it belongs to Kiehl's skin expert series, and was jointly developed by Kiehl's and Columbia university medical college. In the past, safe and efficient sun protection technology mainly refers to preventing UVB radiation, which is the main cause of sun exposure and can be blocked by glass and clouds.
However, daily exposure to UVA rays also carries a high risk. UVA can penetrate glass and even skin surface, which is the chief culprit of photoaging. Therefore, it is very important to choose a full-band sunscreen that can resist both UVA and UVB. Influence of sunlight on epidermis and dermis: 15% UVB can reach the basal layer of epidermis, causing sunburn, while more than 20% UVA can penetrate into dermis all the way, causing skin aging.
What is UVB? B stands for burn.
Skin contact with UVB can lead to sunburn and pigmentation begins to change. The real tanning takes place after 48 hours, and melanin gathers to defend and protect the skin from the sun. Melanin is filtered by absorbing UVB.
What is UVA? "A" stands for aging.
UVA rays make the skin age ahead of time, that is, "photoaging". Long-term exposure to UVA can lead to fine lines, roughness, lack of elasticity, or pigmentation. Repeated sun exposure will damage cells, make them gradually lose the ability to make collagen, and accelerate the phagocytosis of collagen by cells. After continuous exposure to UVA, the skin will lose its elasticity and become slack, and wrinkles will begin to appear inside the facial muscles. These are all symptoms of solar elastic tissue degeneration, which is a premature aging of superficial and middle dermis, which can destroy collagen and elastin of skin, but it takes many years to appear.