Whitening ingredients, girls of any age are keen on whitening themselves. The so-called: a white cover a hundred ugly! But not everyone is born with white skin, so many women will choose certain products to help them whiten and understand the ingredients that can whiten.
Whitening ingredients 1 hydroquinone
The role of hydroquinone is to help inhibit melanin, and it is also considered to be the most effective component to reduce and eliminate pigmentation. Generally speaking, the concentration of hydroquinone in skin care products is 0.5%-2%.
Vitamin a and its derivatives
Most studies show that vitamin A (an alcohol) or various A-acid prescription products are very effective for skin spots.
Some dermatologists have suggested that skin care products containing A acid will have an impact on the development of the fetus. Therefore, some opinions suggest not to use whitening products during pregnancy.
But the fact is: A-acid products are generally used by dermatologists, and generally regular skin care products do not contain A-acid. Therefore, there is no skin care product specifically for pregnant women, and normal skin care products will do.
Fruit acid and salicylic acid
The concentration of fruit acid is 4%- 10% and salicylic acid is between 1%-2%, which is the most effective. Fruit acid and salicylic acid can not only accelerate the cell metabolism of the outer skin, but also directly inhibit the formation of melanin. Therefore, many facial makeup or toning water also contains fruit acid and salicylic acid.
Most dry skin, especially sensitive skin, will change color due to acid. In fact, choosing the right concentration of products will not only cause skin sensitivity, but also help the skin to waste keratin metabolism and inhibit melanin production.
Rhododendronic acid
The concentration of rhododendron acid used in skin care products is generally 15%-20%. Generally speaking, azalea acid is very effective in treating skin acne and pigmentation. At the same time, the effect of azalea acid combined with alcohol A, fruit acid and other components will be better.
arbutin
Speaking of arbutin, everyone is familiar with it. Most whitening products contain arbutin. In fact, arbutin is also a derivative of hydroquinone, which also has the effect of inhibiting melanin.
But there is an important problem: there is no report about the whitening effect of arbutin concentration at present. That is to say, although arbutin is used in the product, we don't know whether it has whitening effect.
This is why arbutin is the most common ingredient in whitening products.
vitamin C
Vitamin C, as an effective skin antioxidant, also has the effect of inhibiting skin melanin production. At the same time, vitamin C has many forms. For example: fat-soluble vitamin C, levovitamin C, ascorbic acid C, glucose ascorbic acid, etc. For example, SK2 bulb contains ascorbic acid glucoside.
nicotine
Nicotinamide is a very popular whitening ingredient in recent years. Nicotinamide is a patented component of Procter & Gamble Group. For example, the light-sensitive white bottle of Olay and the whitening products of SK2 bulb group all contain nicotinamide.
Nicotinamide generally works when the concentration is greater than 2%, but at least 3% is needed to achieve whitening effect. However, nicotinamide is intolerant to some people, and it is easy to cause redness and tingling.
In addition, nicotinamide will be hydrolyzed into nicotinic acid in solution with PH less than 6, which will be more irritating. Therefore, it is not recommended to use nicotinamide products with acid-containing skin care products.
Skin care products with whitening effect are basically the above categories. It should be noted that the whitening ingredients of most skin care products can not be achieved by just one ingredient.
Vitamin C and its derivatives are the most commonly used whitening ingredients 2.
Vitamin C (ascorbic acid, the most effective of which is its left-handed and right-handed optical structure, also called L- ascorbic acid) has whitening effect for both internal and external use.
Principle: inhibit melanin synthesis, reduce melanin, improve skin color by increasing collagen content, reduce vascular permeability and reduce inflammation, so it also has a good effect on inflammation and red blood spots.
Safety: Generally speaking, it is safe, but high concentration will be irritating.
Effectiveness: effectiveness
Disadvantages: unstable, easy to oxidize, damaged by light and decomposed.
Similar: VC derivative, milder and more stable. Common ones are VC ether, magnesium/sodium ascorbate phosphate (MAP, SAP), ascorbate glucoside (AA2G) and ascorbate palmitate (AP).
The most practical arbutin and vitamin B3
α-arbutin is effective and stable, and its limited addition is below 7%, generally around 3%, which can inhibit the activity of melanocytes and reduce the production of melanin. Mild effect, low irritation, but occasional adverse reactions. Generally speaking, it is safe and effective.
Vitamin B3, nicotinamide, nicknamed "anti-dermatitis factor", can inhibit the transfer of melanin to keratinocytes, and also has many improvement effects. Experiments show that topical application of 2% nicotinamide for 8 weeks reduces sebum by 23%, reduces pores by 9%, significantly increases collagen, enhances skin barrier, is non-irritating, has stable properties and is easy to prepare. Compared with retinoic acid, it has obvious advantages in improving skin appearance.
Tranexamic acid, chemical name tranexamic acid, is effective for both internal and external use. On the one hand, it can inhibit melanin production, but the most important thing is to stop bleeding, which has a very good effect on chloasma, especially on pigmentation caused by vasodilation and rupture. It is also irritating to some people. People over 55 years old, allergic patients, patients with thrombosis and those with kidney problems should take it orally with caution.
Blackening principle of whitening ingredient 3:
The so-called tanning, in fact, is that when thermal radiation or sunlight irradiates the skin, it stimulates and activates melanocytes located in the basal layer.
Melanocytes contain pigment particles, and melanosome is synthesized in rough endoplasmic reticulum, which will catalyze tyrosine tandem reaction to produce melanin protein.
At the same time, tyrosinase will lose its activity and serve as a transporter to transfer it to keratinocytes.
The more melanin protein is transferred to keratinocytes, the darker the skin color.
After people with the same skin color are exposed to the sun for the same time, why are some people tanned and some people's skin has not changed much?
This is related to how to whiten and prevent blackening, because the blackening of skin mainly depends on the amount of melanin produced and the amount of melanin transferred into keratinocytes.
That is, the more melanin is produced and transferred to keratinocytes, the darker the skin color and the lighter the color.
Therefore, it can be seen that the best way to whiten skin is to isolate the production of melanin and reduce the number of melanin transferred into keratinocytes.