Dermatological Analysis: Best Serums With Vitamin C

Many of the best skincare products have a common ingredient, vitamin C. You’ve surely seen it in the INCI of various anti-aging products!

And it’s no wonder it’s so popular, as vitamin C is a powerful antioxidant that stimulates collagen production and helps reduce the signs of aging by repairing damage caused by free radicals and the sun.

It’s so effective, it can even help protect your skin from future damage (although it’s not to be confused with a substitute for sunscreen). The result is brighter and firmer skin, with fewer fine lines and wrinkles, and a more even skin tone.

Many dermatologists recommend applying it daily, as there is strong evidence that long-term use of vitamin C topically is associated with better skin texture and quality.

There are many serums vitamin C to choose from , each with a concentration and a type of vitamin C different . The problem is that many of the products do not work because they are not well formulated.

It is essential to find a balance between a high percentage of vitamin C to increase collagen production, but without going overboard to avoid redness and irritation. So you can get the results you want, without harming your skin.

So that you do not have to try all the serums on the market, I am going to analyze the best-selling products of the big brands, looking only at their INCI (list of ingredients).

In this article the three best options are analyzed, and the rest I only put a summary, with a link to the complete analysis so that whoever wants to can read it calmly.

I am only going to analyze each ingredient once, so if it is already explained in another analysis, I will put a link so you can read it.

I recommend that you do not stay alone in the analysis, since later I talk about vitamin C, its types, its benefits and the main problems it generates, as well as other issues related to serums.

The Best Serums with Vitamin C

  • Nezeni Cosmetics Vitamin C Serum
  • Vitamin C Facial Serum from Oz Naturals
  • Vitamin C Ester Serum by Perricone MD
  • Sesderma C-VIT Liposomal serum
  • Kiehl’s Powerful Strength Line Reducing
  • Mad Hippie Vitamin C Serum
  • CE Ferulic Antioxidant Serum from SkinCeuticals
  • Medik8 Antioxidant CE-Tetra Serum
  • Ascorbyl Glucoside Solution 12% from The Ordinary
  • Vitamin Serum 100 of Nutreplus
  • Phytorelax Multi Vitamin Facial Serum

Best: Nezeni Cosmetics Vitamin C Serum

Check price on the laboratory’s website

The serum of Nezeni Cosmetics combines the antioxidant vitamin C,  the super – hydrating hyaluronic acid , and aloe vera regenerant to create a product that protects, regenerates, illuminates, moisturizes and softens skin wrinkles throughout the day.

Its benefits? Restores moisture to the skin, plumps, and the face brightens as the benefits of vitamin C take effect.

I have chosen this serum as the best option with vitamin C for several reasons.

First, it has a high concentration of vitamin C, specifically the stable derivative  of ascorbyl glucoside , one of the best forms of vitamin C out there.

It is a derivative that eliminates the side effects of ascorbic acid, such as irritation and redness. So it can be used without problems by all skin types, even sensitive ones.

On the other hand, it is a serum that is correctly packaged , in an airless, opaque format and with a dispenser to better extract the amount of product to use.

Another thing that I like is that it includes a good amount of other active ingredients, such as hyaluronic acid, aloe vera

So you can see everything it includes, here is the INCI and its exhaustive analysis:

INCI’s analysis shows that the formula strives to use the highest concentration of natural and active ingredients possible .

The 3 most important assets, vitamin C, hyaluronic acid and aloe vera are at the top of the list, something that should be established in all cosmetics.

In addition, it totally avoids parabens, sulfates, phthalates, as well as silicones. Of course, it does not have toxic or harmful ingredients, and its level of preservatives is very low .

This can be easily seen by its expiration date. Unlike the vast majority of cosmetics, those of this Spanish brand do have an expiration date that you can see on the packaging. And even if we do not open the bottle, it expires after 2 years because it includes few preservatives.

You already know (because I have told you ad nauseam) the problem of the combined effect of the highly recommended ingredients . And preservatives (along with silicones, ceramides and alcohols) are one of the main responsible for this effect.

Although the official organisms in Europe regulate these ingredients individually, so that they do not have a too high concentration, and can cause diseases; the truth is that there is no type of control over the accumulation of several of these ingredients collectively.

Because the vast majority of us use more than one cosmetic product a day. And the combined effect of these small harmful proportions can take a toll on our health in the long run.

The point is that the fewer preservatives (and harmful ingredients) we apply, the better. And Nezeni Cosmetics Vitamin C Serum can be considered a safe cosmetic.

With regular use once or twice a day, you will notice its brightening and plumping effects in no time .

The skin is more radiant and luminous than ever, and it does not lack nutrition and hydration because the product is full of emollients and moisturizers that keep the skin moisture.

It is perfect for any skin type, as it is non-comedogenic, hypoallergenic and aloe vera calms irritation and relieves dryness and itching.

In short, it is a high-end serum that is a good derivative of vitamin C and is in a large proportion. In addition, it is surrounded by other highly recommended assets.

Vitamin C Facial Serum by Oz Naturals

Oz Naturals serum is another of the options that we liked the most to take care of our skin, but it is in second place because it does not reach the quality and effectiveness of Nezeni Cosmetics .

It also includes a derivative of vitamin C and hydrating hyaluronic acid, although we like more the result produced by the type that the previous brand has chosen.

It has 20% vitamin C, specifically the derivative sodium ascorbyl phosphate, a good form of vitamin C that is not irritating.

According to the brand, it brightens and protects while fighting free radical damage and delaying skin aging.

Another positive point is that it is properly packaged, in an amber glass container , with a dropper, to better dose the amount of product to use.

In addition to this asset, it includes other antioxidants such as green tea, vitamin E, or Astaxanthin.

So you can see everything it includes, here is the INCI and its exhaustive analysis:

Oz Naturals serum formula has few ingredients, and the vast majority of them are spot on.

In addition, it also avoids parabens, sulfates, phthalates, synthetic fragrances, as well as silicones and PEGs.

But  I have seen an ingredient that can be irritating, although it is unlikely that it is, as its effects are counteracted with calming ingredients.

All OZ Naturals products are not tested on animals, another point in their favor.

However, its effects take longer to be visible, and it does not leave the skin as hydrated as the previous one . In fact, I have noticed that its moisturizing power is quite low.

Its texture is more liquid, and I find it more difficult to apply and spread it.

Without a doubt, it is a good option, although I like the previous one better.

Vitamin C Ester Serum by Perricone MD

Perricone MD is one of the most famous and popular cosmetic brands in the United States, devised by dermatologist Nicholas V. Perricone to treat aging problems caused by inflammation.

From his passion for healthy and youthful skin, the Vitamin C Ester Serum was born, a fat-soluble product that is supposed to be absorbed much better into the skin.

It is a serum to use in the morning , as it can even out uneven skin tone, brighten and reduce the appearance of wrinkles.

And after this introduction, we are going to analyze its INCI, what is really going to tell us if it is a serum that is worth what it costs, or not.

I am happy to see vitamin C in second place on the list , and it has also chosen Tetrahexyldecyl Ascorbate as a vitamin, a more powerful option than L-asorbic acid and other vitamin C compounds, which also has a higher penetration rate .

It also has a range of active ingredients, such as squalane, hyaluronic acid, vitamin E and various antioxidants, although some of them are not in the proportions that I would like.

On the positive side, it has no parabens, PEGs, irritants, or toxic ingredients . They also don’t have too many preservatives, but it does go over fragrances.

Although that silicone and that alcohol that are above should not be in such a high proportion, the overall product is good. No worries about the combined effect.

I only have one drawback: its price exceeds € 100 . This means that not everyone can afford it.

Sesderma C-VIT Liposomal serum

I’m sorry (and to the great dismay of all her fans), I cannot recommend a serum as popular as Sesderma’s C-VIT. The reason is clear, it includes too many harmful ingredients, both for the skin and for long-term health.

Although it has good assets, such as an antioxidant, hyaluronic acid, and a peptide (in addition to vitamin C, of ​​course), and these are in good proportions, it is not enough for the formula to be good and work.

Various irritants and sensitizers, alcohols, PEGs, and two toxic ingredients are more than enough to reject a cosmetic; even more so if we assume that we are going to use it every day (several times a day).

You can enter the complete technical analysis in the following article: Sesderma C-VIT Liposomal serum, Analysis and Alternative .

Kiehl’s Powerful Strength Line Reducing

The star of the Kiehl’s serum is vitamin C, very present in the entire formula; Although we are also led to believe that hyaluronic acid will reduce our wrinkles and fine lines.
But when analyzing the ingredients, we know that this active little or nothing will be able to do in its low concentration.

However, the effect of a smoother and softer skin is achieved, it is possible thanks to the silicones, which are very present in the product. This effect, unfortunately, goes away with the wash.

Thanks to vitamin C, the skin is illuminated and has a more uniform texture, but if you need the serum to do something else for you, it will not achieve it. Not in the long term.

And there is still the question of the ingredient that generates free radicals in the presence of oxygen, something that would harm our skin.

You can enter the full technical analysis in the following article: Kiehl’s Powerful Strength Line Reducing, Analysis and Alternative .

Mad Hippie Vitamin C Serum

Another great option as a vitamin C serum is Mad Hippie, a natural cosmetics brand that formulates all its products with one goal: to include the maximum active ingredients to make them more effective.

That’s why it includes vitamin C in the first place, and it also has hyaluronic acid, vitamin E, several antioxidants and anti-inflammatories.

He does not lie by promising something and then not fulfilling it, and in the formula there is no trace of parabens, synthetic fragrances, PEGs, SLS and other undesirable ingredients.

I only put one catch, that there is a preservative that can irritate. Hope it is not a problem for sensitive skin.

You can enter the full technical analysis in the following article: Vitamin C Serum by Mad Hippie, Analysis and Alternative .

CE Ferulic Serum Antioxidant by SkinCeuticals

The choice of one of L’Oreal’s brands focuses on active ingredients, reducing its INCI to a minimum. Just 12 ingredients with 5 very interesting active ingredients.

Vitamin E, Ferulic Acid, Pro-Vitamin B5, and Hyaluronic Acid complement Vitamin C to create a good antioxidant blend.

Although it is true that the active ingredients could be in better proportions, the discordant note of the formula is put by the irritating and toxic ingredients that it includes.
For the latter is that I would not recommend the serum.

You can enter the full technical analysis in the following article: CE Ferulic Antioxidant Serum from SkinCeuticals, Analysis and Alternative .

Medik8 Antioxidant CE-Tetra Serum

Two unique active principles (vitamin C and E) on which falls the task of combating the damage caused by the sun, increasing the production of collagen, the elasticity and the density of the skin.

Vitamin C is in a magnificent proportion, however, vitamin E is in the last position, which still remains in sixth place.

If it were not for the two silicones that I mention in the summary, and that it would not be bad to include some other active principle, we would be facing a very interesting serum.

The only downside that could be the price. I honestly don’t think these ingredients are worth what they charge for it.

You can enter the complete technical analysis in the following article: CE-Tetra Antioxidant Serum by Medik8, Analysis and Alternative .

Ascorbyl Glucoside Solution 12% from The Ordinary

A serum that is lacking in assets, not because of its concentration, but because of its quantity. There is only vitamin C, and it is present in the form of Ascorbyl Glucoside, so it is less effective than other more powerful forms.

The results will be very weak, improving the tone and appearance of the skin, but little else. I don’t think it’s powerful enough to remove or even reduce wrinkles.

In addition, it is most likely a fairly irritating formula (both for the skin and for the eyes) due to its high composition of irritating ingredients, since it does not have any calming agents that can counteract this effect.

Serum is cheap, but it is not what I am looking for.

You can enter the full technical analysis in the following article: Ascorbyl Glucoside Solution 12% from The Ordinary, Analysis and Alternative .

Vitamin Serum 100 of Nutreplus

I wanted to analyze the INCI of the best-selling and recommended option on Amazon to see if its success was well founded, but I was disappointed.

It may have two forms of vitamin C, and some other active ingredient, but they are not in the concentration that I would like, nor are they surrounded by good ingredients.

From irritants to toxic I have found myself in the analysis. And the most dangerous thing is that an ingredient can create benzene with the presence of vitamin C. I certainly am not going to risk checking it, and I advise you to do the same.

Here below you have the link to the analysis so you can check it out for yourself.

You can enter the full technical analysis in the following article: Nutreplus Vitamin C Serum, Analysis and Alternative .

Phytorelax Multi Vitamin Facial Serum

A multivitamin serum that has vitamin C, A and E, in addition to hyaluronic acid . Unfortunately, neither vitamins nor hyaluronic acid are in an adequate ratio to achieve its great benefits.

There are too many emollients, lubricants and conditioners, and I think they focus more on the look, fragrance and color of the serum, than its effectiveness.

At best, I would rate it as a moisturizer, although there are much better moisturizers, as it has too many irritating, allergenic and potentially toxic ingredients .
It would definitely not be a serum that I would recommend.

You can enter the complete technical analysis in the following article: Phytorelax Multi Vitamin Facial Serum, Analysis and Alternative .

Why use a vitamin C serum?

Vitamin C has a host of benefits for the skin.

Improves the appearance of the skin by firming it . Vitamin C is a very important element in the formation of collagen, the protein that keeps skin looking younger and more supple. By adding vitamin C to skin cells (fibroblasts), collagen synthesis is increased, achieving firmer and smoother skin, with a more rejuvenated appearance.

Delays premature aging and the formation of wrinkles . Vitamin C is a powerful antioxidant that works against free radicals, stubborn molecules that make you look older than you really are. Some of these free radicals are produced by pollution, oxygen, and damage from the sun.

The role of vitamin C is to neutralize these free radicals by creating a kind of protective barrier so that they do not come into contact with the skin and damage it.

Blurs dark spots and brightens skin . Vitamin C serums help reduce hyperpigmentation and skin discoloration, which means they naturally lighten age or sun spots.

Ascorbic acid is known to inhibit the synthesis of melanin (the pigment that gives skin and hair its color), unifying skin tone. In some cases, vitamin C can also prevent redness that comes from sun damage, and brighten the skin.

Increases the effectiveness of sunscreen and strengthens the skin’s defenses against UV exposure . Vitamin C offers effective protection against harmful UV rays. However, it should not be used as a sunscreen, but rather to complement it.

It can also be used after a sunburn, to repair damage and reduce discoloration and fine lines.

It is clear that incorporating vitamin C into your daily skincare routine will allow you to look younger, firmer and more even skin for longer.

The problem with vitamin C

One of the main problems with vitamin C is that its natural form, ascorbic acid, is quite unstable and breaks down easily .

It becomes unstable simply by coming into contact with air or other oxidizing agents. And this instability can make the product totally ineffective .

Oxidation, at best, could render the product useless, and at worst, it could increase the number and formation of free radicals that damage the skin.

The first step in oxidation is that ascorbic acid is converted to dehydroascorbic acid, better known as DHAA. DHAA is as unstable as ascorbic acid in water-based formulas, and it can further break down into other by-products, such as acids that make the skin’s pH more acidic, which can irritate the skin and lead to redness. .

In old or poorly stored or prepared products, vitamin C is totally ineffective, and it will degrade as long as you use it.

In reality, only highly concentrated formulas containing more than 10% vitamin C can provide the adequate amount of ascorbic acid to be effective .

In products that have a high concentration of vitamin C, even if some of it is degraded, you can still get a good dose of it. However, you have to be careful, as it could be irritating.

Fortunately, laboratories have been able to solve the problem of ascorbic acid instability and oxidation by creating more stable derivatives that cause little irritation.

Types of vitamin C

These are the types of vitamin C available:

Ascorbic Acid or L-Ascorbic Acid

Ascorbic acid is one of the most researched forms of vitamin C when it comes to skin care, but it is also the most unstable and can be quite irritating in high concentrations.

In serums with Ascorbic Acid, look for concentrations between 5 and 15% of the product. If your skin can handle it, it is undoubtedly the asset to look for. Just make sure the serum is not oxidized.

Still, most companies prefer to use vitamin C derivatives, because they have a longer shelf life.

The ideal vitamin C derivative should be able to penetrate the skin and release L-ascorbic acid in an amount strong enough to stimulate collagen formation; as well as staying stable and not irritating the skin like vitamin C.

Magnesium Ascorbyl Phosphate or Sodium Ascorbyl Phosphate

Magnesium Ascorbyl Phosphate and Sodium Ascorbyl Phosphate (more or less the same) are water-soluble derivatives of vitamin C; for many, the best form of vitamin C to use in skin care products.

It is less irritating and more stable than vitamin C. Even better, sodium (or magnesium) ascorbyl phosphate has the same potential as vitamin C to aid in collagen synthesis, and can be used in concentrations between 1 and 20 % as effective as ascorbic acid.

In the end, for those who have sensitive skin or don’t want irritation or redness, sodium ascorbyl phosphate is probably a better option than pure vitamin C.

Still, keep in mind that sodium (or magnesium) ascorbyl phosphate can degrade when not properly stored or exposed to light and air. Respecting the expiration date on the container is essential to ensure that the product continues to work.

Ascorbyl Palmitate

This form is the most widely used fat-soluble (oil-soluble) derivative of vitamin C in skin care products.

It is not irritating to the skin and is much more stable than vitamin C. However, although it has good antioxidant properties, it does not stimulate collagen synthesis as much as ascorbic acid and other derivatives.

So if you have to choose an oil-based product that contains vitamin C, make sure it includes ascorbyl palmitate.

Tetrahexyldecyl Ascorbate

It is a form of vitamin C that has been modified to be more lipid soluble. This modification allows it to penetrate the skin better.

The problem with many of the topical forms of vitamin C is that they are soluble in water, and cannot pass through the lipid-rich skin barrier to reach the dermis, the deeper layers of the skin where the actives should act.

Tetrahexyldecyl ascorbate is able to successfully penetrate the epidermis, and move into the lower layer called the dermis. It is in the dermis where collagen is produced, and vitamin C can stimulate the synthesis of this protein.

It is a relatively new derivative, so at the moment it does not have any side effects. At the moment we know that it is a more stable form of vitamin C, capable of penetrating deeper into the skin safely, and with minimal irritation.

Ascorbyl Glycoside

Ascorbyl Glucoside has a structure in which the C2-hydroxyl group of L-ascorbic acid is masked with glucose. Once inside the skin, ascorbyl glucoside breaks down into ascorbic acid and glucose; therefore, it has all the benefits of ascorbic acid.

What is not clear is how much concentration of vitamin C this decomposition process leaves behind. What is known is that it has a greater stability than pure vitamin C, which tends to decompose in the presence of heat, light, oxygen and at certain pH levels.

This means that ascorbyl glucoside lasts more than twice as long as other forms of vitamin C, and therefore has a longer effect.

The question that arises is obvious:

Are derivatives as effective as natural vitamin C?

The short answer is a resounding YES. The long answer needs a little more explanation. Attentive.

Derivatives are vitamin C that has a component (for example phosphate or palmitate) added to help prevent the breakdown of pure vitamin C. Those components act as bodyguards that protect the core of vitamin C from degradation.

As a result, they are more stable and less irritating to the skin, while offering the same benefits, such as collagen synthesis, skin repair, and reduction of sun spots.

It should also be noted that even stabilized derivatives of vitamin C can degrade sooner or later, although their shelf life is considerably longer than pure vitamin C.

How to use a vitamin C serum

Antioxidant-rich serums such as vitamin C are best suited to counteract pollutants as well as the dangerous effects of the sun’s UV rays. That is why it is advisable to use them twice a day , every day, just after cleansing the skin and applying the toner.

Most experts recommend using the serum in the morning because it protects and strengthens the skin throughout the day, although antioxidants accumulate in the skin no matter when they are applied. If applied in the morning, the serum protects against daytime damage, but at night it can also combat the damage that the skin has suffered during the day.

Apply a small amount of the serum to your fingertips, and spread it over the problem areas of the face. Once it’s fully absorbed, you can apply your favorite moisturizer to seal in the most superficial layers of your skin.

Make sure to apply sunscreen over the serum in the morning, before going outside.

How long does it take for the vitamin C serum to take effect?

By introducing vitamin C serum into your daily care routine, you will start to see some noticeable changes and improvements in your skin. It usually takes about three weeks for the serum to fully take effect, but it also depends on your skin type.

Other recommended ingredients in a vitamin C serum

Vitamin C alone can help with aging skin problems, but it is usually accompanied by other active ingredients to reinforce and enhance the benefits.

It is advisable to opt for a product that has other active ingredients or beneficial ingredients, such as antioxidants, especially if you are fighting against the problems of aging.

In some combinations, antioxidants can reinforce each other and go beyond what they can do on their own. We have seen products that combine vitamin C with ferulic acid and vitamin E (two great antioxidants).

Another great addition is hyaluronic acid , which helps to deeply hydrate the skin to fill in fine lines and wrinkles.

Other restorative ingredients are aloe vera, green tea, rosehip, etc.

That these serums include several assets will not harm your skin, in the worst case, they simply will not cause any benefit, so look for a product that covers all fronts.


  • Hyaluronic acid
  • Ferulic acid
  • Astaxantine
  • CoQ10
  • grenade
  • Coconut, Jojoba , Sunflower Oil
  • Aspen bark
  • Aloe vera


  • Rosehip oil
  • Aloe vera
  • Green tea
  • Coconut oil
  • Chamomile
  • Rose oil
  • Liquorice


  • Willow bark (salicylic acid)
  • Rose oil
  • Witch hazel
  • Lavender
  • Turmeric
  • Tea tree oil
  • Salvia extract
  • Green tea


Keep in mind that normally, the more vitamin C there is in the serum, the less active ingredients the manufacturers will add (to keep the cost of production), and vice versa.

Of course, the choice will depend on whether or not you use other serums in your skincare routine. If you only use one product, it is a good idea to have a mixture of several active ingredients (vitamin C, ferulic acid, hyaluronic acid, peptides, etc.).

If you use several serums for different concerns, opt for a high concentration of vitamin C, since the other assets will be provided by the other products.

Also, remember that the main factor of aging is the sun , and that as much as vitamin C can act against free radicals and blemishes, it does not replace sunscreen.

You always have to go outside with a SPF50 + sunscreen on top of the serum, and apply it repeatedly at the end of the day, especially if you are going to be outdoors.

Tips when buying a vitamin C serum

In addition to the ingredients, there are other factors that should be taken into account when buying a vitamin C serum. These are the most important:

That it has the right container

Products containing Vitamin C and its derivatives have a sensitivity to air and / or light that causes their quality to degrade at a faster rate if stored incorrectly.

Luckily, there are packaging that helps keep products fresher for longer. The flasks opaque glass dropper, or restricting the air containers are the most common.

The amber or blue colored glass bottles protect the serum from light. Amber colored glass is said to protect slightly more from light than blue colored glass, but the difference is not as significant.

What you should avoid are transparent bottles or containers, which have a lower price for the manufacturer, but the useful life of the serum is shorter.

For the best results with a vitamin C serum, be sure to close it tightly to reduce the amount of air that gets inside and out of direct light.

Try to avoid exposure to moisture, so storing it in the bathroom is not highly recommended. Many people like to keep their anti-aging products with vitamin C in the fridge, but if not, you can also wrap them in aluminum foil.

And of course, make sure you have the expiration date of the product close by, as it is the best indicator to know if the product is still effective or not.

The serum should not be colored

When choosing a serum that contains vitamin C (or any derivative), look for products that are white or colorless in color. This is because any colorant in the formula can hide the signs of oxidation that make the product less effective.

If there is oxidation, the serum will have a yellowish or brownish tint.

Of course, the absence of this color does not guarantee that the product is oxidation-free, since the first oxidation stages are colorless.

Some unethical manufacturers even add color to their products so that the oxidation state cannot be detected, so they can sell oxidized products without you knowing.

However, some only do it for marketing reasons: people associate orange or yellow with vitamin C, so they dye their products to be more aesthetically pleasing.

Still, I recommend avoiding vitamin C products that are not colorless or white. In this way, you can check the state of degradation and, consequently, the effectiveness of your anti-aging product.

It must be suitable for your skin type

Each person has a different skin type, and it must be taken into account when buying a cosmetic. Certain types will do better with vitamin C derivatives, while others will prefer to use the pure form.

You really have to try to find the one that best suits your needs , although you can play it safe by choosing a suitable product for all skin types, or for your skin type in particular.

If you have sensitive skin, a product with a high level of ascorbic acid is more likely to irritate or damage your skin, so you should start with a gentler option.

In this case, it is better to start with a very gentle concentration, and gradually increase it.

On the other hand, there are certain types of skin that perfectly withstand a high concentration of vitamin C from the first moment, even in its pure form.

Generally, normal or oily skin is the most resistant, while dry or sensitive skin needs to start with a lower concentration to avoid irritation and redness.

So the most important criterion is not the percentage but how much% of vitamin C your skin needs for results, and how much it can support.

The pH of the product has to be optimal for its correct absorption

When trying to make a decision on which serum to buy, pH levels should be one of the most important things to consider. The pH level indicates the degree of acidity of the product: the lower the pH, the more acidic the product will be.

The serum must have a pH level of 3.5 maximum (preferably lower), or it will not be able to penetrate the skin, so it must be acidic to be effective, but it can also be irritating for some people.

Skinceuticals is the one that holds the patent for the lowest CE Ferulic serum available on the market, it has a pH between 2.5 and 3.0. However, many of the brands tested are not far above this, with pH levels ranging from 3.0 to 3.5.

They can’t lower it any further because it will violate the patent, but it’s still low enough to be effective.

As for the derivatives, the pH problem is not so important because they can opt for a more neutral pH.

For example, magnesium ascorbyl phosphate has an ideal pH around 5 or 6, which is the pH of our skin. This is the reason why some serums that use derivatives of vitamin C come with a label for sensitive skin.

Many brands have a problem with the pH. The products are not well formulated and the pH is not within the ideal range for optimal penetration of ascorbic acid. The result is that the product is ineffective.

You must know how to read an INCI (List of Ingredients)

The most important part when buying a serum (and any other cosmetic) is knowing what the components of the product are.

For this you have the INCI. However, most cosmetic ingredient lists contain many weird-sounding names that are unlike anything we know of.

Fortunately, there are some tips to help you understand INCI.

First of all, you have to get used to looking at the ingredient list. Just watch. Many people don’t even bother to look at INCI because they think they won’t understand anything.

And it is true that there are many things that you will not understand, but you will also realize that there are ingredients that you do understand, such as parfum or citric acid. The idea is that you get used to looking at at least the INCI.

The cosmetic industry wants to keep its formulas secret. This is understandable, as if not, anyone could make an exact copy of your products. But unfortunately this also means that they do not have to indicate the exact percentage of each ingredient.

Still they have to follow some rules, like listing the ingredients in order of quantity. So the first ingredients are the most important , since the product is mainly composed of them.

Normally the first 8 ingredients are the most powerful , while the rest are only present in very small amounts, although this varies a lot depending on the product.

There are some loopholes that make it difficult to read the INCI. On the one hand, ingredients included with less than 1% can be added in any order that is preferred. This means that if a product contains 0.0001% of a natural ingredient, and 0.99% of parabens, olive oil can be indicated before parabens.

Also, since the cosmetic industry is so secretive, cosmetic companies are still allowed to request that some ingredients not be mentioned in the INCI. Instead, they will be replaced by a seven-number code, or simply “and other ingredients”, making it more difficult, or totally impossible, to know what the product really consists of.

Even with these difficulties, I advise you to read the ingredient list and investigate what each ingredient is and how it works within the formula.

Most can be found on google, you can search them to see what is being said about them, and try to form an opinion on whether they are safe or not. Some of the sources I use are or

Most of the time information will appear in English, but if you don’t know the language you can translate it into Spanish with google translate. It is not so difficult!

By doing this, you can buy a cosmetic product knowingly, and not just because a brand can afford a good marketing campaign.

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Kathie Sand always saw the world of beauty as the terrain on which to build her professional career, a goal that was clear to her when she was only 15 years old. Her great concern to expand knowledge led her to settle in Paris where she studied hand in hand with the best beauty professionals and with the most advanced techniques for skin care.

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