said before that melanin is not a bad person, and you have to maintain a stable relationship with it for a long time. If you seek to be whiter than the "natural skin tone", it often costs too much and even health. However, it is possible to pursue whiteness within the range of "natural skin color".
So the protagonist we are going to talk about today is "melanin." To extend the discussion from melanin, which whitening and spot-lightening products are useful? How does it work?
If you want to whiten, you need to know how melanin is produced, how it is transported, and how it is metabolized, so that you can understand which products or medicines can whiten.
must first know that melanocytes are distributed in the basal layer of the skin and their function is to produce melanin. Under the stimulus state, the melanocytes will activate and begin to try to produce melanin.
Conditions in your own body, such as endocrine, liver disease, pregnancy, tumors, etc., can induce the activation of melanocytes.
Factors outside the body, such as ultraviolet rays, exposure to photosensitive substances, drugs, inflammation, friction, and improper use of cosmetics can also induce melanocyte activation.
UVA can cause tanning and skin aging. UVB can cause sunburn and sunburn. After activation of
, the melanocytes began to try to produce melanin
Source: MedPartner
To do anything, we must first have raw materials! The most important raw material for melanin production is Tyrosine, and most important chemical reactions in the body require the presence of "enzymes" to promote the reaction. The enzyme here is Tyrosinase! In the melanocytes in melanocytes, tyrosine is first synthesized into dopa (DOPA), and then converted into "dark brown pigment" or "eumelanin" (most people say they are melanin). If you are black, it will turn into "Eumelanin", if not, it will usually be "Dark brown pigment." Then the synapses of melanocytes transmit melanin to surrounding keratinocytes. The melanin that is released next will gradually be sent to the epidermis, then gradually move to the epidermis, and finally be metabolized.
Source: Knowing that
melanin takes about "28 days" from manufacture to delivery to keratin. Therefore, generally speaking, it takes one month to evaluate whether the whitening product is effective. If it is effective immediately, it must not only act on the melanin level. If the melanin is unevenly distributed and concentrated together, it becomes the so-called "spot". If the melanin is completely absent in a certain area, it becomes a "white spot". If you want to ask me, you really have to choose one of the two, which one do you want? Of course it is Madara. Pigmented spots can also be lightened by medicine or laser treatment. White spots without melanin are really difficult to fix.
So seeing inside, smart you, you must know what to do! 1. In the " before " of melanin synthesis, attack his mid lane first to directly reduce the production of tyrosinase!
2. In the melanin synthesis " in ", it inhibits tyrosinase, making it difficult to synthesize melanin!
3. In the " post-" of melanin synthesis, it can inhibit the transfer of melanin bodies, or accelerate skin renewal!
The mechanism of melanin production, transportation and metabolism. Source: MedPartner
How to reduce spots? First of all, it should be divided into congenital or acquired! After you understand melanin, you will want to know how to deal with spots?
The important thing is to figure out whether your spots are "congenital" or "acquired."
Congenital spots are more difficult to treat with acquired prevention methods. You must look at the color, depth, and underlying cause of the pigment to determine the treatment method. For example, drugs or lasers are all possible treatment options. If the spots are caused by genes or other medical diseases, they will continue to produce spots, which may not be able to cure them. For example: coffee spots, birthmarks, Ota nevus, and zygomatic brown spots are all congenital spots.
Other spots have a chance to prevent. Freckles and sunburns are relatively easy to deal with. However, chloasma is more troublesome and usually requires active prevention and multiple treatments.
but the truthThe answer is that since "spots" are formed, it means "uneven production or distribution of melanin." Sunscreen and skin care can only "on average" "decrease melanin production or increase melanin metabolism", but the effect of the formed spots is limited. In fact, most conditions still require treatment. However, it is feasible to reduce the spots to a limited extent and rely on sun protection and correct skin care.
Let me introduce to you the ingredients and mechanism of action of whitening agents approved by our country
(1) Whitening agent
that inhibits melanin production
Melanin is the most important type of pigment that affects skin whiteness. Inhibiting melanin production is naturally the most important whitening product. An ultimate goal.
Melanin is produced in melanocytes, and melanocytes exist in the basal layer of the skin epidermis, so this kind of functional ingredients must penetrate into the skin and reach the basal layer to exert its effects. This is a relatively difficult problem to solve The problem is that the natural barrier of the stratum corneum is difficult to penetrate, so this is also a very important reason why many whitening cosmetics are not ideal.
Currently commonly used whitening agents that inhibit melanin production on the market mainly include arbutin and its derivatives, kojic acid and its derivatives, vitamin C and its derivatives, endothelin antagonists, licorice flavonoids, anthocyanins, and green tea , Azalea, grape seed, rhodiola and other plant extracts.
(2) The whitening agent
that blocks the transport of melanin is produced in melanocytes, and the melanosomes will be transported along the dendritic processes of the melanocytes to the surrounding keratinocytes, affecting the skin color.
melanin transport blocker can reduce the transmission speed of melanosomes to keratinocytes, reduce the melanin content of each epidermal cell layer, and achieve whitening effect. Such as nicotinamide, azelaic acid, green tea extract, etc.
(3) Exfoliating agents
This kind of substances soften the stratum corneum, accelerate the shedding of dead cells in the stratum corneum, and promote the metabolism of the epidermis, so that the melanosomes entering the epidermis will fall off with the rapid renewal of the epidermis in the metabolic process to reduce it. The effect on skin color, such as acid, keratinase, etc. Among them, the chemical exfoliation effect of fruit acid is more irritating, and the dosage should not be too large, while keratinase is a biological exfoliant with mild action and generally does not produce irritation. Source of
: Cosmeceuticals
The above three types of substances are whitening agents for melanin production. The first type is to grab the source from the source and inhibit the production of melanin; the second and third types are for the situation where melanin has been produced. The second category is for melanin that has not been transported out of melanocytes, and the third category is for the melanosomes that have been transported from melanocytes to the surrounding keratinocytes. Therefore, these three types of whitening agents have different effects on the three different stages of melanin from scratch to leaving the human body. In addition to , another ingredient that is often used in whitening products is mercury.
Mercury is an ingredient with extremely strong whitening effect and quick effect. However, because of its strong toxicity to the human body, my country has banned the addition of mercury in cosmetics.
In other words, as long as the skin care products you buy are produced by regular manufacturers, mercury is generally not added. However, if you encounter some self-made whitening agents with immediate results, or whitening products from Sanwu manufacturers, you should be more careful. How does
choose safe whitening and spot-lightening products? Speaking of the Kanebo incident,
actually has many new whitening ingredients developed every year. Frankly speaking, most doctors are not familiar with these new whitening ingredients. Here must mention a tragedy in the cosmetics industry a few years ago: the Kanebo incident.
4-(4-hydoroxyphenyl)-2-butanol, 4-HPB for short, is an active substance developed by Kanebo Co., Ltd. of Japan. It can inhibit the formation of melanin and prevent the formation of pigment spots. In 2008, it was approved by the Japanese Ministry of Health, Labour and Welfare (similar to the Ministry of Health) and announced as a medicinal whitening ingredient. The "acid" of azalea is completely different from the "mellow" of azalea, don't get confused!
However, rhododendronol above a certain concentration will interact with tyrosinase to produce toxic metabolites, causing damage to the activity of melanocytes and even inducing cell death. As a result, a large number of people use products containing this ingredient to cause severe white spots. 2013In July 2007, Kanebo announced the recall of this product and will never use it again. Those who want to learn more about this matter can search for "Kanebo Incident". What does the story of
tell us? There are many whitening products, and they are constantly introducing new ones. But if a new ingredient claims to have a "fast whitening" effect, should you be happy or worried? If it were me, I must be worried. Because a new ingredient has not been tested enough, once a problem occurs at any stage from the previous development to the market, the result may be very serious. Fortunately, almost all the victims of the Kanebo incident can be recovered later, but the consequences are disastrous.
So if you want to whiten or lighten spots, please listen to some conscientious suggestions from Uncle Cong:
1. Prevention is better than cure. Sun protection accounts for more than 80% of the importance.
2. Old ingredients are usually safer than new ingredients, and the effect may not be much worse, and they are usually cheaper.
3. Product composition is better to avoid unclear interaction
4. Do not use many whitening products at once
5. Please choose products Look at the active ingredients and the concentration
6. If there are spots, please find out whether it is congenital or acquired, and understand the cause to start symptomatic treatment
7. It is good to pursue whitening, but don't think about it. Natural skin tone is usually a safe bottom line. Pursue more white, often only worse.
8. If you really want to do laser, please consult a regular doctor first. Don't trust the promotion of beauty salons or consultants.
