Recently, a ** has been spread on the Internet. A woman asked experts in the field of skincare when the "hydration lie" would end, and said that "**can't and doesn't need to hydrate". This issue has aroused widespread concern. Today, let's talk about hydration and moisturizing from the perspective of a doctor.
Screenshot of Hot Transmission**.
Before talking about this problem, we need to understand the structure of **.
*ByEpidermis, dermis, subcutaneous tissueConstitute. **The epidermis is the part that is in direct contact with the outside world, and the stratum corneum, clear layer, and granular layer in the epidermis are the key to maintaining moisture.
*Wikipedia.
The stratum corneum generally has a water content of 15% to 25%, which not only prevents the release of water from the body, but also absorbs water from the external environment.
When the water content is less than 10%, it will be difficult to metabolize properly and function will be affectedLike dry land, water, electrolytes, and other substances within are more likely to be lost through. At this time, external harmful substances are also easy to invade, causing a variety of problems, such as itching, allergies, etc.
If the moisturizer is done well, the cells will "absorb the water" and let the "protective film" form again, and the cells will regain their softness and smoothness. Therefore**Hydration is required, especially if it is dry** or exposed to dry conditions.
But,What we usually call "hydration" is simply the hydration of the stratum corneumBecause of the protection of the ** barrier, the moisture basically cannot reach the dermisSkincare products that claim to hydrate the skin are false claims.
We also need to clarify the relationship between hydration and hydration. Moisturizing is mainly to prevent the loss of water on the surface of **, and form a moisturizing film on the outside to lock in moisture, which is also the medical term - reduce"Transepidermal dehydration".。For example, moisturizing is similar to putting a film on land that contains a certain amount of water to prevent the original moisture of the land from being lost too quickly. True "hydration" is different, it is similar to watering the land in order to increase the amount of water from outside.
Many people will find that with long-term use of hydrating products, the dryness does not improve, and it seems to worsen. Why is that? Generally speaking, after cleansing**, the moisture content of the stratum corneum is about 30% when no skin care products are applied, and the use of skin care products can make the moisture content of the stratum corneum reach 70% or 80% in a short period of time.
If you only use hydrating products, such as hydrating sprays, etc., the moisture on the surface will evaporate into the air, resulting in drier products. Therefore, if you want to "quench your thirst" in an air-conditioned room, just to replenish water, the direction of your efforts is not right. Use a moisturizer while hydrating to better lock in moisture and bring long-lasting hydration.
There are many names for skin care water, including toner, astringent water, softening water, functional water, essence water, etc. They mainly have two common functions.
One is hydration。After washing your face, you can temporarily increase the water content of ** with skin care products, and then after applying a moisturizer externally, the water will be blocked in ** to achieve a long-lasting moisturizing effect, which may be better than using a moisturizer alone. Of course, if you don't use this kind of skin care water, just moisturizer to moisturize, it's not impossible.
The other is secondary cleaning, which helps remove any residue of detergent and makeup while adjusting the pH level.
In addition, the water quality in some areas is hard, and washing your face with hard water for a long time will cause harm. Because the pH value of the skin care water is carefully adjusted, it can neutralize the acid-base imbalance caused by various reasons when used on the surface, so that the best state can be achieved. Different names of skincare products will have different effects, so you need to carefully distinguish and choose the one that suits you best.
1 toner
It has a relatively strong function of cleaning and adjusting the pH, which is more suitable for people who often wear makeup, and it is best to dip it in a cotton pad and rub it on the face in one direction. It is best not to apply directly with your hands, as the hands themselves may not be clean enough, and the dirt that has been cleaned is still on the hands or face, which will not achieve the purpose of cleaning.
2 Astringent water
Added with ingredients to help shrink pores and control oil, it is more suitable for oily** use. It should be noted that this type of lotion may contain alcohol, ** sensitive and allergic people need to be careful.
3 softening lotions
It mainly moisturizes and softens keratin, and the cleansing effect is not strong, so you can apply it directly to the face with your hands. Some products have a thicker texture that sits between water and lotion and can have some extra effects before using them in a moisturizer.
4 Emulsions
Lotions and creams have a strong water-locking function, and some also contain ingredients that repair the ** barrier, which are the most mainstream and recommended moisturizing dosage forms. Among them, the biggest feature of the emulsion is its high water content, which can instantly moisturize**, and build a moist sebum film for ** to prevent water loss. Compared to creams, lotions have a more refreshing texture and are more suitable for summer or normal, combination and oily skin.
5 creams
Creams are inherently indistinguishable from lotions, and the morphological changes of the cream are only a matter of process. In addition to the basic functions of moisturizing, some also contain other functional ingredients, such as repairing and anti-wrinkle. Night creams are usually more nourishing than day creams and will feel more oily after application. More suitable for dry autumn and winter use or dry, neutral**.
A good bottle of moisturizer is a must-have for every beauty lover. There are many types of moisturizers on the market, and the main active ingredients are divided into three types: respectivelyEncapsulants, moisture absorbers, and emollients
Encapsulants can form an oil film on the surface of ** to prevent water evaporation, such as petroleum jelly. Hygroscopic agents refer to substances that can absorb water, which can attract deep moisture to the stratum corneum, and can also absorb water from an environment with high water content. Emollients are a class of mild, lipophilic substances that make ** softer and tougher. Different moisturizers are different ratios of these three types of substances.
So how can you tell if a moisturizer is good or bad? There is a simple way to learn from it, and a well-known expert in China once proposed that "you only need to try this product on the face or body."Feelings are the best answer”。A good moisturizer can provide a moist sensation for a long time, and after use** moist, smooth and elastic.
Of course, when choosing any skincare product, you must keep it in mindBuy products produced by regular manufacturers that meet national standardsOh.
**: This article is a work of Popular Science China-Star Project.