Most of the masks on the market today refer to the wet wipes like compress-type masks. The efficacy of the mask is understood by most people as moisturizing, nutrition, whitening, promote repair, exfoliation, improve skin texture, etc., while the national regulatory agencies for the efficacy of the mask is not mandatory, as long as the health of qualified, safe and harmless can be marketed and sold. Theoretically speaking, with the right mask, can indeed bring some help to the skin. First, wet treatment – medical “mask” for the treatment of skin diseases of the medical principle Medical aspects of the mask is the most important application of cold and wet treatment. Dermatology clinically commonly used cold wet compress material is soaked in sterile water, saline, boric acid, Levano or magnesium sulfate solution, one of the gauze or non-woven cloth, mainly used for exudative dermatosis or skin physical damage to the early treatment, but also can be used to reduce localized edema of the skin. For example, in the early stages of pediatric eczema, there is often a lot of oozing and crusting, accompanied by severe itching, and then wet compress treatment is the first choice of local treatment. In addition, foreign countries also contain tranexamic acid, hyaluronic acid and other components of the efficacy of the drug mask, can be used for the treatment of some facial dermatosis and facial laser treatment after care. Some medical studies have also shown that a localized wet environment is conducive to the healing of skin wounds, and so there are also collagen masks for medical purposes such as Travelexa and Keflexa. The role of cold and wet compresses can be roughly summarized as follows: 1, reduce skin temperature, contraction of dilated capillaries, reduce skin flushing and inflammation. 2, the wet compress material can absorb the skin, so that the skin can be used for the treatment of wounds. 2, wet dressing material can adsorb the surface of the skin to cause allergic substances and metabolic waste, etc., to alleviate skin contact allergies, and play the effect of cleaning and itching. 3, with the gradual evaporation of moisture, wet dressing material solute concentration gradually increased, can absorb the exudate material of the acute phase of skin inflammation, and play the effect of astringent swelling. 4, wet compresses in a short period of time to rapidly increase the water content of the stratum corneum of the skin, increasing the penetration of drugs in the stratum corneum, can promote the effective ingredients of drugs through and absorption. Second, the mask can indeed increase the penetration of effective ingredients Skin surface lipids, keratinocytes, intercellular lipids and natural moisturizing factors that are involved in the four parts constitute a complete skin barrier. They moisturize the skin, prevent excess water from evaporating outward from the skin, but also inhibit the growth of harmful microorganisms on the skin surface. Due to the hydrophobic nature of lipids and the tight junctions between cells, water and water-soluble molecules, as well as substances with higher molecular weights, can hardly pass through this barrier. However, in some cases, we would like to maximize the penetration of substances that are beneficial to the skin, and the easiest way to do this is to physically encapsulate them. Encapsulation increases the water content of the stratum corneum, causing swelling of the keratinocytes, increasing the cellular space, expanding the intercellular space and ultimately connecting the originally isolated cavities, creating a “pore” like structure in the keratinocyte interstitial space, which makes it easier for water-soluble substances and even slightly larger molecular weight substances to pass through it. The sealing of the mask can make some of the nutritional or therapeutic ingredients contained in the penetration and penetration increase, which is the main theoretical support for the possibility of the effect of the mask. Third, the fluorescent substances in the mask Just because the mask to wet the way to increase the permeability of the skin, the mask in the substance may be applied to the skin surface than simply penetrate more quickly, so the safety of the mask is a consumer needs to be very concerned about. One of the items in the CCA’s assessment report, “fluorescent phenomenon”, has triggered a debate among consumers. The original intention of the assessment is well-intentioned, because in the early years, some unscrupulous manufacturers have added fluorescent whitening agents to the masks, so that consumers appear to have “whiter” skin after using the products, and fluorescent whitening agents are not legal cosmetic additives. Although there is no evidence that it is harmful to the skin, it is still a cause for concern for consumers. Fluorescent whiteners, also known as fluorescent dyes, are a class of complex organic compounds that absorb ultraviolet light to release a blue to green band of light, thereby neutralizing the yellow color and making the dyed material look whiter. It should be noted that all fluorescent whiteners can emit fluorescence, but not all fluorescent substances are fluorescent whiteners. The CCA report also points out that “based on the lack of testing methods for fluorescent whitening agents in cosmetics, the comparative test can only detect whether the sample has fluorescence phenomenon.” The fluorescence phenomenon is a common physical phenomenon of natural substances, natural fluorescent substances are commonly found in nature. Even many everyday foods can fluoresce, such as free amino acids and vitamins that may be similarly contained in face masks. There is no more famous fluorescent agent than quinine in tonic water, a drink used to make cocktails, which can emit a beautiful blue fluorescence when exposed to ultraviolet light. And tonic water is not harmful to the human body. Therefore, consumers do not need to be too panicked about the fluorescence phenomenon produced by the mask. Fourth, the mask is not a moisturizer Masks can increase the water content of the stratum corneum for a short time, but can not block the evaporation of the skin surface. In fact, the skin’s water mainly from the dermal blood circulation supply. Adults daily evaporation of water through the skin surface of about 240 ~ 480 ml (half a bottle of mineral water), the loss of these water is not like sweating can be noticed, so it is known as the “inconspicuous water loss”. The integrity of the skin barrier, as we mentioned earlier, is the main factor in ensuring a certain level of moisture in the skin. As long as the skin barrier is intact, meaning that the structure of the stratum corneum and the surrounding lipid components function properly, the skin will maintain normal moisturization. Through the application of masks and can not achieve the effect of moisturizing, at best, can be said to be to the stratum corneum “rehydration”, but this effect lasts a very short period of time. From the CCA mask report we can also see that the vast majority of brands of masks in the uncovered, with the extension of time, the skin moisture content are dramatically exponential decline, completely unable to play “keep” wet effect. As for hydration, the skin’s moisture content after bathing can also reach quite high levels. Therefore, the use of masks as a means of moisturizing, hydration is very low cost-effective. If you don’t follow up with a moisturizing milk/cream after applying a mask, it can make your skin feel even drier. In fact, drinking water, paste cucumber, masks can not give skin moisturizing, moisturizing mainly rely on lipids. Fifth, the mask is not a necessity on the market as a daily product sales of non-medical mask products are very diverse, as a maintenance cosmetics, not everyone needs to use. Medical masks are mainly used for therapeutic moisturizing, while the efficacy of daily masks is mainly in hydration and promote penetration. For moisturizing, the “3-minute principle” of dry skin care (use moisturizing milk/cream within 3 minutes of drying the skin after bathing) will be more beneficial than applying masks diligently to moisturize the skin; for promoting the penetration of active ingredients, it is mainly due to the type and efficacy of active ingredients contained in the mask. For example, in terms of nutrition, whitening, repair, exfoliation, skin texture improvement, etc., the research and development of these effective ingredients are sometimes very complex and need to be discussed in relation to specific ingredients. Therefore, consumers are advised to choose products from regular manufacturers and pay attention to their full ingredient list when purchasing facial masks. From the perspective of improving the quality of life and mood pleasure, women need a mask to appease the inner; and from the perspective of skin care, do a good job of cleaning, moisturizing, sunscreen based on the mask can bring potential benefits to the skin. Conclusion: If you need to use masks, be sure to choose regular products and avoid overuse.