Vitamin C. How one of the best antioxidant works?

When choosing a skincare product, everyone saw a jar that promises to highlight “the radiance” or “reduce” pigmentation. And most likely, everyone has a product with this magical component. We are talking about vitamin C.
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Vitamin C is one of the best and most needed antioxidants. Our skin needs it. The body can’t reproduce it on its own, and we get a dose of this vitamin along with food — fruits, cabbage, broccoli, and others. But only a small portion of vitamin C from food gets into the skin.
So what can vitamin C do with our skin?
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As we said, vitamin C is a strong antioxidant. UV rays, the environment, smoking, and other bad habits are harmful to our skin and cause “oxidative stress”. Vitamin C is one of the antioxidants that helps neutralize it and prevent skin damage.
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Vitamin C protects the skin from photoaging. UV rays in the skin cause free radicals (reactive oxygen species), which, when accumulated in the skin, are highly toxic. It means that they damage proteins, nucleic acids, and cell membranes. Free radicals activate MMP enzymes that decompose collagen fibers, and collagen production is reduced.
All this leads to clinical manifestations of photoaging of the skin, such as rough skin texture, pigmentation, deep wrinkles, etc..
Studies have found that vitamin C reduces the production of MMP, which reduces collagen damage. In one double-blind study, applying 10% of vitamin C for 12 weeks reduced the signs of photoaging and deep wrinkles.
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The anti-aging effect of vitamin C is also due to its involvement in collagen production. This vitamin is essential for the synthesis of collagen (types 1 and 3), and, most importantly, vitamin C is needed to form enzymes that stabilize and cross-link collagen fibers. It not only prevents the destruction of collagen but also helps to synthesize it. That’s why vitamin C is useful not only for protection but also in the fight against photoaging of the skin.
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What else can vitamin C do? Don’t forget one of the most popular effects is anti-pigmentation. The tyrosinase enzyme is responsible for the formation of melanin, a skin pigment. Vitamin C can suppress it, thus lightening the skin

This ability has been proven in studies, but vitamin C is still not as strong in lightening the skin as, for example, hydroquinone. However, vitamin C is safer and has a positive effect on the condition and production of collagen.

What is C+E?

Vitamin C works perfectly with another antioxidant, equally important for the skin — vitamin E.Vitamin C is able to restore vitamin E, so this combination works great. Vitamin E is a fat-soluble antioxidant, and it plays a huge role in protecting membrane cells from oxidative stress. Both vitamin E and vitamin C are rapidly depleted by UV light. These two antioxidants complement each other and enhance the photoprotective effect.
In a 2005 study, it was confirmed that the addition of ferulic acid to C and E perfectly stabilizes and enhances the photoprotective effect of duo vitamin C and E. The three of them make up one of the most effective combinations of vitamin C.

However, vitamin C also has a reverse side. There are certain conditions for vitamin C to begin to create its magic in the skin.
First, vitamin C is even more capricious than retinol. It is extremely unstable and rapidly destroyed by sunlight and oxygen.
Ascorbic acid is a water-soluble molecule, so it penetrates heavily into the skin due to the hydrophobic nature of the stratum corneum. But the pH (acidity) level can help with stability and penetration. At pH 3.5 or lower, ascorbic acid can penetrate well into the skin (according to the same study in 2005). To remain stable, ascorbic acid, in addition to low acidity, will require a bottle of dark glass or another material that protects against UV rays. Either an airless bottle or with minimal oxygen access will be useful.
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Ascorbic acid is a well-researched working ingredient, but it is difficult to formulate because of its water-soluble nature and instability. Trying to create an ideal, stable, and active formula of ascorbic acid, cosmetic chemists are in constant search of the best derivative of vitamin C. But stability at higher levels of acidity is not yet an indication that it works perfectly. Like retinol, whose activity depends on how well it is transformed into retinoic acid, vitamin C derivatives must also be transformed into pure ascorbic acid, which is capable of performing miracles with the skin.

Therefore, along with stability, the ability to transform into ascorbic acid determines the effectiveness of new forms of vitamin C.
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There are so many forms of vitamin C on the market, and we are sure that there will be new forms whose activity will be the same as in pure vitamin C, but much more stable. We will analyze the most popular and interesting derivatives of vitamin C to help you choose the most suitable one for you.

Two forms of Vitamin C

Vitamin C has three essential and useful properties for the skin: it inhibits melanin production, protects cells from damage by UV rays (photoprotective), and stimulates collagen production (neocollagenesis). That’s why it is so popular, and that’s why companies are developing new stable forms of vitamin C that will not only meet the requirements of stability but will also show all three effects of ascorbic acid.
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Yesterday we discussed ascorbic acid, and today we will begin to discuss the forms of vitamin C in more detail. We will start with two forms, or rather salts of ascorbic acid: magnesium ascorbyl phosphate (MAP) and sodium ascorbyl phosphate (SAP).
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MAP. The first thing I want to note is that it really has excellent stability, up to pH 7. The bad news is that MAP penetrates the skin worse than ascorbic acid. But for example, microdermabrasion and regular peeling can improve the penetration of all forms of vitamin C. However, penetration into the skin is not the only condition for the effectiveness of the derivative. As we mentioned, they must be converted to pure ascorbic acid. And the good news again, in vitro studies have proven that MAP is converted well to pure vitamin C. We will be waiting for research performed on real people. As for effectiveness, there are no studies that confirm the photoprotective effect, but it can stimulate collagen synthesis like pure vitamin C (in vitro studies). The most interesting thing is that studies in real people (in vivo) have proved its ability to lighten pigmentation. MAP is a rather promising form of vitamin C. It is not a choice for those who want to enhance skin protection from UV rays, but a good component for those who want to lighten pigmentation, improve skin quality, and reduce wrinkle depth. This form of vitamin C is worthy of attention. But don’t forget, it doesn’t penetrate well into the skin, so regular peeling is one of the important procedures to improve its effectiveness.
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SAP, as well as MAP, has excellent stability but bad penetration into the skin.

Unlike MAP, SAP has good photoprotective activity confirmed in-vivo (on real people), but it is weaker than pure vitamin C. SAP can stimulate collagen production but weaker than MAP. There is also evidence from the manufacturer that it helps fight hyperpigmentation. It turns out to be worse than MAP and pure ascorbic acid in all its parameters, which may not make it the best option to use. But SAP has a small trump card as it has significant antibacterial activity against bacteria causing acne (P.acne), which was proven in a 2005 study. In a 2009 double-blind study, 5% SAP was proven to be as effective in treating acne as 0.2% retinol. The combination of these two components showed even greater activity. The study also confirmed that SAP reduces the oxidation of sebum caused by UVA rays.
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This form of vitamin C will be of interest to those who struggle with acne. It may not be strong in the fight against photoaging, so it is better to use ascorbic acid and other more promising derivatives. But if we are talking about acne-prone skin, this might be a useful form of vitamin C.

Two more derivates

It is an esterified form of vitamin C, a mixture of ascorbic acid and ethyl group — ethyl ascorbic acid (EAC). Such a combination makes this component very stable, and most importantly, soluble both in water and oil. As we mentioned before, one of the conditions to be effective is that the derivative must penetrate into the skin. This form of vitamin C penetrates well into the skin, which was proved by research from the manufacturer, as well as independent research on animals. And apparently, EAC can penetrate the skin better than ascorbyl glucoside, another promising derivative (we will talk about it later). So, EAC fulfills the first two requirements for the effectiveness of vitamin C derivatives — it is stable and easily penetrates the skin. What about the third and very important condition: the ability to transform into pure ascorbic acid? Unfortunately, here we have limited research from the manufacturer. Of course, we believe him, but we would still like to see independent research.
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The manufacturer claims that EAC transforms into pure ascorbic acid, works as a good photoprotector, and can stimulate collagen production. However, the amount of data is still limited to state this exactly. But there is great news! The lighting of pigmentation is the most promising effect of EAC. It has been proved not only by the manufacturer’s research but also by clinical studies in humans (in-vivo), which is very significant. The study showed that 2% EAC can even out skin tone and reduce pigmentation.
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EAC is a little researched, so we would like to see more evidence, especially clinical studies. It is definitely a promising derivative of vitamin C, and it is worth including it in your routine, especially if it aims to reduce hyperpigmentation and protect against UV rays.
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The next derivative, as we mentioned, is Ascorbyl Glucoside. It is also very promising and is one of the best derivatives of vitamin C; we can even say that it is a bit better studied than EAC.

Ascorbyl glucoside is a stable form of vitamin C. In-vitro studies have proven its ability to penetrate the skin (although slightly worse than EAC). And this is the first plus. Another very important benefit is that it is converted into pure vitamin C in the skin (in-vitro study). It means that we can expect all three ‘magic’ effects of vitamin C: antioxidant protection (photoprotective), stimulation of collagen production, and reduction of melanin production. The photoprotective effect is proved by studies in humans (in-vivo), even though ascorbyl glucoside was slightly weaker than SAP (sodium ascorbyl phosphate), it is still very good news. In vitro studies have confirmed that ascorbyl glucoside does stimulate collagen production and reduces melanin production. It has all the beneficial effects of ascorbic acid.
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That is why this form of vitamin C is one of the most attractive. Yes, it is weaker than pure ascorbic acid, but it is stable, and it is much easier to formulate in products. Most studies have been performed in-vitro so far, so we look forward to information about studies on humans to confirm its effectiveness. We think everyone will like this form: those looking for a protective product and those who need an active anti-aging component.

A controversial component

The next form of vitamin C is ascorbyl palmitate. Despite being very common, its activity and usefulness are very different from other derivatives.

What is wrong with it?
Studies have shown that its stability is comparable to pure ascorbic acid, which means it is not stable as an independent component. Like AA (ascorbic acid), its stability is very dependent on additional components in the product. Ascorbyl palmitate is a very controversial component. The good news is that it penetrates the skin, but there is no evidence that it is converted to pure AA in the skin. Research in vitro showed that it could stimulate collagen production, so we can conclude that a very limited part of palmitate ascorbyl still can be converted to pure AA. And this is the only good thing to say about this form of vitamin C. Well, almost. Ascorbyl palmitate is an antioxidant that provides a photoprotective effect, which is really good, and again there is BUT. A 2002 study showed that contrary to its antioxidant effect, probably the lipid component (palmitic acid) of ascorbyl palmitate, promotes the formation of oxidized lipids, toxic to the skin after exposure to UVB rays. In fact, it can become toxic to the skin under sun exposure. This makes it not the best candidate for a daytime product.
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We think that low doses of this component are generally harmless. But when it comes to visible results, vitamin C is needed in higher concentrations or a derivative that can very actively increase vitamin C levels in the skin.
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One of such derivatives is Tetrahexyldecyl Ascorbate (or Ascorbyl tetraisopalmitate)
It is a stable, fat-soluble form of vitamin C, which means it will actively penetrate deeper layers of the skin, and won’t just remain on the surface. Research from the manufacturer on human cells (ex-vivo) has proven this. As for another condition of effectiveness for the derivative, Tetrahexyldecyl Ascorbate is converted to pure vitamin C in the skin (in-vitro).

This is good news and means that we can expect all three effects of vitamin C — photoprotective effect, collagen stimulation, and lightening of hyperpigmentation. It is another very promising form of vitamin C — stable and effective, especially since the lightening effect was proved by a study conducted in humans, a study from the manufacturer. Even though this form has only been tested in vitro, except for the lightening effect, we believe that this is one of the best forms that can seriously compete with pure vitamin C. We hope that more research on real people will help prove this.

This form will appeal to everyone who wants to introduce vitamin C into their routine, especially those looking for a worthy active ingredient to reduce hyperpigmentation and get radiant skin

Aminopropyl Ascorbyl Phosphate is a very little researched derivative of vitamin C. It is a stable, water-soluble form. The only study from the manufacturer on real people (in-vivo), which is very good, indicates that this derivative is excellent at lightening hyperpigmentation and reducing the depth of wrinkles. That is, we can assume that it is converted into pure vitamin C in the skin. We could say that this derivative is worth a try, but again, independent research is needed to prove its activity in cosmetics when applied to the skin.

There are many other forms of Vitamin C that can be used in the care of your skin, such as Ascorbyl phosphate palmitate, whose lightening ability has been proven in real people (in-vivo); it is a stable derivative that also penetrates well. It is a really promising derivative, but very rarely found in products.

What about your products with Vitamin C? The review

BRIGHTENING TURMERIC + C ENLIGHTEN SERUM is a serum based on vitamin C derivative — Magnesium ascorbyl phosphate. It is a good option for lightening the skin as it is the lightening feature of MAP that is best studied. The product has antioxidants and soothing ingredients, turmeric extract can also help to even out the tone. As for disadvantages, MAP does not penetrate very well on its own into the skin; it would be ideal to see components that could increase penetration. So do not expect a pronounced lightening pigmentation effect. Also, it contains citrus essential oils; the aroma is very pleasant but can be a challenge for sensitive skin.

Naturium vitamin c 22% serum. It is an aqueous solution of vitamin C, or to be more accurate, pure vitamin C and sodium ascorbyl phosphate (SAP). It is stated that the product contains 22% of vitamin C, but apparently, this is the total concentration of the two forms. Glutathione and vitamin E are essential antioxidants that improve the stability of pure vitamin C and increase the photoprotective effect of all forms. It’s a very useful combination, but it’s not the best pH (5.4 in this product) for a pure form of vitamin C, even though the manufacturer indicates the encapsulation of pure vitamin C. We don’t think that you can expect high effectiveness of this product compared to other serums based on pure vitamin C (stabilized). But, it can be a good choice for skin with acne. As we pointed out in our SAP analysis, it is very useful in treating acne and modulating acne-prone skin. The product has good moisturizing ingredients (beta-glucan and hyaluronic acid) and gold. Gold isn’t an active ingredient, but just a dye that gives shine, so don’t confuse the light glow from this component after the first application with the action of vitamin C. SAP does not penetrate the skin very well, and penetration enhancers in the product are not enough, so its effect will mainly be on the surface. Plus, pure vitamin C will not last long at this pH level, although it is very delicate to the skin. There are no fragrances or essential oils, so it’s a very delicate formula.

Insta natural C serum is a water-based serum of vitamin C derivative Sodium ascorbyl phosphate. As indicated in the previous post, this form is weaker than pure vitamin C, but it is very beneficial for acne-prone skin. SAP does not penetrate very well into the skin, so again we can emphasize that there are not enough penetration enhancers for effectiveness, even with good additional plant extracts like licorice (an excellent lightening component), tea extract and the two most important vitamin C companions — ferulic acid and vitamin E. This serum will be a good protective agent against UV damage with a slight lightening effect. You shouldn’t expect stimulation of collagen production or a more intense lightening of hyperpigmentation from this product.

Dermadoctor 20% Vitamin C Serum. We can say that this serum is an excellent combination of a stable derivative of ethyl ascorbic acid. It penetrates perfectly into the skin, plus it contains a penetration enhancer — ethoxyl glycol. It also has two antioxidants that double the photoprotective effect of vitamin C — ferulic acid and Vitamin E. All conditions have been met to count on the high effectiveness of this product, especially on the lightening effect of this form of vitamin C, as it is well-researched.

And you can find our selection here

Several questions at last

Before starting our Vitamin C week, we asked you what you want to know about this component. We have chosen the two most interesting questions, in our opinion, the answers to which we did not disclose in the posts, and we are answering them now.
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🍊 Skin with rosacea and Vitamin C
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Skin with rosacea is very demanding (capricious) Vitamin C in high concentrations can be aggressive to the skin. If you want to add vitamin C to your care, do not use a concentration above 10 percent, and a product must not contain alcohol (for example, obagi has alcohol in their serums with vitamin C). Compliance with these conditions is sufficient to care for skin prone to rosacea without causing a negative reaction. It is better to use waterless products with vitamin C since they do not have a pH. Water products with vitamin C need a low pH (3.5) for better penetration into the skin, but this pH can irritate the skin.
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🍋 How to include vitamin C in care if you use acids, retinol, and niacinamide?
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If you regularly use acids (AHA / BHA), retinol and niacinamide, then there are some nuances in the use of vitamin C. First, especially important, you need to distinguish between the use of acids and retinol with vitamin C, as it can additionally irritate the skin when it comes to a high concentration. For example, retinol at night, vitamin C and niacinamide in the afternoon. As for acids, if this peeling is washable, then it is also better in the evening if it is an acid serum, then give time to normalize the pH of the skin after the application of acids (usually 15–30 minutes is enough to be able to apply vitamin C). But then again, all of this only works when it comes to the irritating effects of vitamin C. Perhaps, the product that caused acne contains some other ingredients that can provoke them. You should check that too