Whitening is a lifelong pursuit for some beauty lovers. On Monday, Anan helped everyone summarize some common misunderstandings about whitening and learn about scientific whitening methods.
The color of human skin is affected by the pigment system. Melanin is the product of melanocytes. The content and distribution of these pigments are the main factors that determine skin color. Melanocytes are one of the important components of the skin. They have dendritic processes. The synthesized melanin is secreted into keratinocytes through dendritic processes. It is excreted with the shedding of keratinocytes and exists in the basal layer of the epidermis, affecting people's skin color. .
Whitening products are mainly designed around inhibiting the formation and transport of melanin and accelerating melanin shedding. Today let’s take a look at some common whitening ingredients in skin care products.
The “star” ingredient, niacinamide
Speaking of niacinamide, many people know that it can whiten. It is also one of the most common ingredients in whitening products. Niacinamide can "hide" melanin to achieve a whitening effect. Niacinamide, also known as vitamin B3, is a type of B vitamin. Its whitening mechanism mainly includes: 1) inhibiting the formation of melanin granules; 2) inhibiting the transfer of melanin to keratinocytes; 3) accelerating the transfer of melanin in keratinocytes to the stratum corneum and promoting the shedding of the stratum corneum.
Clinical observation studies show that skin care products containing nicotinamide can further reduce the number and extent of spots on human skin. Long-term use of skin care products containing nicotinamide can promote skin color fading and produce freckle removal and whitening effects.
Cosmetics containing niacinamide are not suitable for everyone
Pregnant women should not use it. Excessive use of nicotinamide may cause fetal malformations. It is also not recommended for use during breastfeeding.
Cannot be used by those whose skin cannot tolerate it. Niacinamide may contain the impurity niacin, which may cause skin redness, swelling, heat pain, allergies, etc. For safety reasons, if you are using nicotinamide products for the first time, you can first apply it to the skin on the inside of your arms or behind your ears to test whether you are allergic.
Melanin blocker, arbutin
Arbutin is an additive in whitening cosmetics. It was originally discovered from ursi ursi leaves and is the main active ingredient in ursi ursi leaves, so it is named arbutin. Arbutin can effectively inhibit biological tyrosinase in the skin and block the formation of melanin. In addition, arbutin can also directly combine with tyrosinase to accelerate the decomposition and metabolism of melanin. Arbutin can effectively reduce skin pigmentation and remove spots and freckles. It is currently the main raw material commonly used in whitening cosmetics.
Choose arbutin-containing products scientifically
1. Look at the content
In fact, the higher the arbutin content, the better, because arbutin is photosensitive, and if the concentration is too high, there will be certain safety risks. When the content of arbutin is too high, it can cause adverse reactions such as skin erythema, stinging, and contact eczema. Therefore, as a whitening ingredient in cosmetics, it is safer if the content of arbutin is within 2%.
2. Look at the ingredients
Arbutin can be divided into three categories according to different structures: deoxyarbutin, α-arbutin and β-arbutin. Deoxyarbutin has the strongest anti-melanin effect, but it easily releases hydroquinone during its use, which may lead to the risk of allergies or cancer. Many countries have listed deoxyarbutin or its toxic metabolite hydroquinone as banned ingredients. Therefore, Products containing deoxyarbutin should not be used.
In addition, in terms of activity, α-arbutin is 10-15 times more active than β-arbutin. In terms of safety, α-arbutin is more stable and difficult to discolor and degrade. Therefore, buying products containing α-arbutin will be more effective, which means it is more friendly to the human body.
3. View save
As mentioned above, hydroquinone, the decomposition product of arbutin, is a banned ingredient in the country. Due to hydroquinone's high toxicity, strong irritation, and carcinogenic risks caused by long-term exposure, my country's "Safety Technical Specifications for Cosmetics" (2015 Edition) lists hydroquinone as a banned raw material for cosmetics.
Whitening products containing arbutin will slowly decompose at high temperatures of 40-50°C, producing very small amounts of hydroquinone, which can cause harm to the human body. Therefore, attention should be paid to the storage environment of cosmetics containing arbutin, and they should be placed in a low temperature and dark place to avoid risks.
