COSRX The Vitamin C 23 Serum Ingredients Explained
Overview
What it is
Serum with 34 ingredients that contains hyaluronic acid, niacinamide, Vitamin C and Vitamin E
Cool Features
It is cruelty-free and reef safe
Suited For
It has ingredients that are good for fighting acne, anti aging, dry skin, brightening skin, sensitive skin, oily skin, reducing pores, scar healing, dark spots and better texture
Free From
It doesn't contain any common allergens, fragrances, parabens or sulfates
Fun facts
COSRX is from South Korea. This product is used in 269 routines created by our community.
We independently verify ingredients and our claims are backed by peer-reviewed research. Does this product need an update? Let us know.
Ingredient List (34)
Water, Ascorbic Acid 23%, Propanediol, Dimethicone, Tromethamine, Panthenol, Ethyl Ether, Squalane, Caffeine, Sodium Chloride, Sodium Hyaluronate, Sodium Sulfite, Disodium EDTA, Glutathione, Adenosine, Acetyl Glucosamine, Gardenia Florida Fruit Extract, Allantoin, Dextrin, Tocotrienols , Tocopherol, Elaeis Guineensis Oil, Butylene Glycol, Arginine, Niacinamide, Pentylene Glycol, Alcohol Denat., Helianthus Annuus Seed Oil, Glycyrrhiza Glabra Root Extract, Methyl Trimethicone, Carthamus Tinctorius Seed Oil, Camellia Japonica Seed Oil, Daucus Carota Sativa Root Extract, Beta-Carotene
You should know
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Ingredient Info
Contains Alcohol
Ingredients in this product that are types of alcohol:
Contains Silicon
Ingredients in this product that are types of silicon:
Fragrance Free
This product is free of fragrances 🎉
Sulfate Free
This product is free of sulfates 🎉
Paraben Free
This product is free of parabens 🎉
Contains Oils
Ingredients in this product that are types of oil:
Not Malassezia Safe
Ingredients in this product that are not malassezia safe:
Reef Safe
This product is free of ingredients that damage reefs 🎉
EU Allergen Free
This product is free of EU allergens 🎉
Non Vegan
This product is not vegan 😥
Cruelty Free
This product is cruelty-free 🎉
Ingredients Overview
Ingredients Explained
Water. It's the most common cosmetic ingredient of all. You'll usually see it at the top of ingredient lists, meaning that it makes up the largest part of the product.
So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.
You'll also recognize water as that liquid we all need to stay alive. Talk about multi-purpose! If you see this, drink a glass of water. Stay hydrated!
Learn more about WaterAscorbic Acid is is pure Vitamin C. This form makes up the largest amount of vitamin C found naturally in our skin.
Not only is vitamin C great for your overall health and immune system, it also has plenty of benefits on your skin.
Vitamin C is best used for brightening skin. It improves dark spots, acne scars, and hyperpigmentation. This is because it blocks the process of skin darkening when exposed to UV.
Remember: Vitamin C should not replace sunscreen!
Your skin uses vitamin C to build collagen. Collagen is one key component in having a strong skin barrier and plump skin. Vitamin C also plays a role in regulating collagen, thus making it effective in improving wrinkles and fine lines.
Ascorbic acid shows potent antioxidant activity. As an antioxidant, it helps fight free-radicals. Free-radicals are molecules that may damage your skin cells. These antioxidants also protect skin against UV damage.
The best formulations include Vitamin E and/or ferulic acid. These two ingredients help stabilize and provide a boost in the benefits of ascorbic acid. This is because ascorbic acid becomes unstable when exposed to UV and air. In fact, you can tell your ascorbic acid has oxidized when it turns an orange-yellow color.
Ascorbic acid is generally compatible with other ingredients. However, using ascorbic acid with other active ingredients might cause irritation. Two ingredients: copper ions and benzoyl peroxide, will inactivate ascorbic acid completely.
Read more about other types of Vitamin C:
Foods rich with vitamin C include oranges, strawberries, broccoli, bell peppers, and more. When consuming Vitamin C, your skin receives a portion of the nutrients.
Learn more about Ascorbic AcidPropanediol helps absorb ingredients into your skin, boosting their benefits. It can act as an emollient, making your skin softer. Propanediol can help products last longer by boosting the properties of preservatives within the formulation.
Propanediol is not likely to cause sensitivity and considered safe to use.
It is derived from corn or petroleum with a clear color and no scent.
Learn more about PropanediolDimethicone is a silicone used for making products smooth and silky. It also has the added benefit of sealing in hydration. The amount of dimethicone found in beauty products is considered safe and non-comedogenic, meaning it won't clog pores.
Dimethicone has been found increase absorption in skin, boosting the benefits of other ingredients. While there is concern for the safety of dimethicone, the levels used in skincare are safe for use.
Tromethamine is an aliphatic compound. An aliphatic compound is an organic compound with open-chained carbon atoms. It is synthetically created. Tromethamine is used to balance pH and improve texture.
As an emulsifier, Tromethamine prevents oil and water ingredients from separating. This helps stabilize the product and elongate a product's shelf life. Tromethamine also makes a product thicker.
Tromethamine helps balance the pH level of a product. Normal pH level of skin is slightly acidic (~4.75-5.5). The acidity of our skin is maintained by our glands and skin biome. Being slightly acidic allows our skin to create an "acid mantle". This acid mantle is a thin barrier that protects our skin from bacteria and contaminants.
Oral Tromethanmine is an anti-inflammatory drug but plays the role of masking, adding fragrance, and/or balancing pH in skincare.
1,3-Propanediol, 2-amino-2-(hydroxymethyl)-
Learn more about TromethaminePanthenol (also referred to as pro-vitamin B5) is a common ingredient that helps hydrate and soothe the skin.
lt is a humectant, meaning that it helps the skin attract and retain moisture.
Another benefit is the anti-inflammatory abilities. This means that it's great for sensitive, irritation-prone skin.
Once oxidized, panthenol converts to pantothenic acid. Panthothenic acid is found in all living cells.
Learn more about PanthenolSqualane is an emollient that helps the skin hold onto moisture. It's an oily liquid that occurs naturally in certain types of fish and plant oils.
Because squalane boosts hydration in the skin, it also comes with plenty of benefits: it is an antioxidant and can help fight free radicals and skin damage. Squalane is also found to have a detoxifying effect when applied.
Squalane comes from squalene, which occurs naturally within the sebum of our skin. It is one of the oils our skin produces to keep itself hydrated. Squalane is the hydrogenated version of squalene and has a longer shelf life.
Research shows that squalane is non-irritating (even at 100% concentration).
In general, it's a fantastic ingredient. It does a great job at hydrating the skin, and it's suitable for those with sensitive skin.
The source of squalane may impact malassezia / fungal acne. This is because olive oil derived squalane can contain impurities such as fatty acids and plant waxes. Sugarcane derived squalane is recommended for anyone with malassezia concerns.
Is squalane vegan? This depends on the source. Squalane can be derived from both plants and animals. Most squalane used in skincare comes from plants.
Please note: the source of squalane is only known if disclosed by the brand. We recommend reaching out to the brand if you have any questions about their squalane.
Read more about squalene with an "e".
Learn more about SqualaneCaffeine is most associated with coffee, tea, and cacao. In skincare, it helps with calming inflammation and anti-aging.
Caffeine is an antioxidants, which help with the signs of aging. This is because antioxidants help fight skin-damaging free radical molecules.
While caffeine is used to treat cellulite and and dark circles, further studies are needed to prove this. It has been believed to help with these skin conditions due to its ability to dilate blood vessels and increase blood flow.
Some studies are looking into caffeine's ability to protect against UV rays.
Learn more about CaffeineChances are, you eat sodium chloride every day. Sodium Chloride is also known as table salt.
This ingredient has many purposes in skincare: thickener, emulsifier, and exfoliator.
You'll most likely find this ingredient in cleansers where it is used to create a gel-like texture. As an emulsifier, it also prevents ingredients from separating.
There is much debate on whether this ingredient is comedogenic. The short answer - comedogenic ratings don't tell the whole story. Learn more about comegodenic ratings here.
The concensus about this ingredient causing acne seems to be divided. Research is needed to understand if this ingredient does cause acne.
Scrubs may use salt as the primary exfoliating ingredient.
Learn more about Sodium ChlorideSodium Hyaluronate is hyaluronic acid's salt form. It is commonly derived from the sodium salt of hyaluronic acid.
Like hyaluronic acid, it is great at holding water and acts as a humectant. This makes it a great skin hydrating ingredient.
Sodium Hyaluronate is naturally occurring in our bodies and is mostly found in eye fluid and joints.
These are some other common types of Hyaluronic Acid:
Learn more about Sodium HyaluronateSodium Sulfite is a preservative. Preservatives help prevent mold and bacteria from growing in cosmetics.
This ingredient has been shown to break the bonds in hair, acting as a natural straightener.
It is commonly used in food. It should be noted sodium sulfite degrades both vitamins B1 and E.
Fun fact: Sulfites are naturally occuring in wine.
Learn more about Sodium SulfiteDisodium EDTA plays a role in making products more stable by aiding other preservatives.
It is a chelating agent, meaning it neutralizes metal ions that may be found in a product.
Disodium EDTA is a salt of edetic acid and is found to be safe in cosmetic ingredients.
Learn more about Disodium EDTAGlutathione is an antioxidant naturally found in our bodies. It is also naturally occurring in plants, animals, fungi, and some bacteria. As an antioxidant, Glutathione helps prevent oxidative damage to parts of our cell.
While Glutathione is said to help with skin lightening, the results from research are inconclusive. Further studies are needed.
Adenosine is in every living organism. It is one of four components in nucleic acids that helps store our DNA.
Adenosine has many benefits when used. These benefits include hydrating the skin, smoothing skin, and reducing wrinkles. Once applied, adenosine increases collagen production. It also helps with improving firmness and tissue repair.
Studies have found adenosine may also help with wound healing.
In skincare products, Adenosine is usually derived from yeast.
Learn more about AdenosineAcetyl Glucosamine is an antioxidant and humectant. It is a form of Vitamin C.
Acetyl Glucosamine helps the skin produce hyaluronic acid and boost hydration.
Antioxidants help fight off free-radicals, molecules that may damage skin cells.
When paired with niacinamide, Acetyl Glucosamine has been shown to be effective at reducing discoloration.
Read more about other types of Vitamin C:
Learn more about Acetyl GlucosamineWe don't have a description for Gardenia Florida Fruit Extract.
Allantoin plays a role in soothing and moisturizing the skin. Because of this, it is often added to products with strong active ingredients.
Some studies have shown this ingredient can promote wound healing with higher concentrations.
Allantoin is derived from the comfrey plant but produced synthetically for cosmetic products to ensure purity.
Learn more about AllantoinDextrin is used to thicken a product and helps bind ingredients together. It is created from starch and glycogen.
As an emulsifier, dextrin prevents ingredients from separating. This helps elongate a product's shelf life.
Studies show coating UV filters with dextrin prevents these ingredients from being absorbed. This helps UV ingredients last longer on the skin.
Learn more about DextrinWe don't have a description for Tocotrienols.
Tocopherol (also known as Vitamin E) is a common antioxidant used to help protect the skin from free-radicals and strengthen the skin barrier. It's also fat soluble - this means our skin is great at absorbing it.
Vitamin E also helps keep your natural skin lipids healthy. Your lipid skin barrier naturally consists of lipids, ceramides, and fatty acids. Vitamin E offers extra protection for your skin’s lipid barrier, keeping your skin healthy and nourished.
Another benefit is a bit of UV protection. Vitamin E helps reduce the damage caused by UVB rays. (It should not replace your sunscreen). Combining it with Vitamin C can decrease sunburned cells and hyperpigmentation after UV exposure.
You might have noticed Vitamin E + C often paired together. This is because it is great at stabilizing Vitamin C. Using the two together helps increase the effectiveness of both ingredients.
There are often claims that Vitamin E can reduce/prevent scarring, but these claims haven't been confirmed by scientific research.
Learn more about TocopherolElaeis Guineensis Oil comes from the African Palm tree. This tree is native to Western and Southwestern Africa.
This oil is rich in antioxidants such as Vitamin E. Antioxidants may help with anti-aging.
The Vitamin E and fatty acid content give palm oil a skin-hydrating property. Emollients help trap moisture in by creating a film on the skin.
Palm oil is created by either squeezing the fruit or crushing the kernel at the center of the fruit. In the 1800s, archaeologists discovered a 6000 year old Egyptian tomb containing palm oil.
Palm oil is controversial due to its social and environmental impacts. Several organizations are working to make palm oil harvest more sustainable, such as the RSPO.
Learn more about Elaeis Guineensis OilButylene Glycol (or BG) is used within cosmetic products for a few different reasons:
- It is a solvent, meaning that it helps to dissolve other ingredients. This also enhances the absorption of the product into one's skin.
- It is a humectant, which means that it helps attract moisture into the skin.
- It helps improve product application.
Overall, Butylene Glycol is a safe and well-rounded ingredient. It is unlikely to irritate skin, and works well with pretty much all other ingredients.
Arginine is an amino acid that is important for human development. Your body uses is it to produce hair keratin and skin collagen.
As a cosmetic ingredient, Arginine has antioxidant properties and can also help repair damaged skin. This ingredient is derived either synthetically or from animals.
Arginine isn't fungal acne safe when used in the presence of other lipids (fats, fatty acids, oils, esters, etc). Oils and fats occur naturally within the skin, so take caution when using Arginine if you're prone to fungal acne.
Learn more about ArginineNiacinamide has emerged as an all-star ingredient due to its many benefits.
It is known to treat acne by reducing inflammation. It also helps fade dark-spots and strengthen the skin by promoting the growth of the ceramide barrier.
Other benefits include smoothing wrinkles and minimizing redness.
The cherry on top? Niacinamide can also help build keratin, a protein that keeps skin firm.
When incorporating niacinamide into your routine, look out for concentration amounts. Typically, 5% niacinamide provides benefits such as fading dark spots. However, if you have sensitive skin, it is better to begin with a smaller concentration.
Niacinamide can be mixed with other ingredients to boost benefits. For instance, it has shown to be effective when used with copper, folic acid, and zinc to treat acne.
Learn more about NiacinamidePentylene glycol is typically used within a product to thicken it. It also adds a smooth, soft, and moisturizing feel to the product. It is naturally found in plants such as sugar beets.
The hydrophilic trait of Pentylene Glycol makes it a humectant. As a humectant, Pentylene Glycol helps draw moisture from the air to your skin. This can help keep your skin hydrated.
This property also makes Pentylene Glycol a great texture enhancer. It can help thicken or emulsify a product. Emulsifiers help stabilize a product. It does this by preventing certain ingredients from separating.
Pentylene Glycol also acts as a mild preservative and helps to keep a product microbe-free.
Some people may experience mild eye and skin irritation from Pentylene Glycol. We always recommend speaking with a professional about using this ingredient in your routine.
Pentylene Glycol has a low molecular weight and is part of the 1,2-glycol family.
Learn more about Pentylene GlycolAlcohol Denat. is an alcohol with a denaturant property. It is created by mixing ethanol and other additives. It has a low molecular weight and will evaporate quickly. This helps other ingredients become better absorbed and dry once applied.
Alcohol Denat. is volatile and may cause irritation. It helps draw out natural oils in skin and dry out your skin.
One study from 2005 found adding emollients to propanol-based sanitizer decreased irritation.
Alcohol is antibacterial by nature. This can help preserve products and increase their shelf life.
Other types of astringent alcohols include:
Learn more about Alcohol Denat.Helianthus Annuus Seed Oil is the oil derived from the seeds of a Sunflower. Sunflower seed oil is non-fragrant. It is an emollient, meaning it helps to soften the skin.
Sunflower seed oil contains many fatty acids. The fatty acids found in sunflower seeds include (from highest amount to least): linoleic acid, myristic acid, palmitic acid, stearic acid, arachidic acid, oleic acid, and linolenic acid.
These fatty acids help the skin create ceramides. Ceramides play a role in repairing the skin barrier.
Helianthus Annuus Seed Oil helps moisturize the skin. This in turn helps the skin look more rejuvenated and smoother.
Sunflowers are rich in vitamin E.
Historians believe Indigenous cultures of North America domesticated sunflowers before corn. Thus they relied on sunflower oil for a variety of uses. One such use is moisturizing skin and hair.
Sunflower seed oil may not be fungal acne safe. We recommend speaking with a professional if you have any concerns.
Learn more about Helianthus Annuus Seed OilGlycyrrhiza Glabra Root Extract is an extract of the roots of Licorice. It has been found to have several benefits such as skin hydrating, conditioning, and soothing.
One component, glabridin, has extra potent antioxidant and soothing properties. It has also been found to block pigmentation from UVB rays in guinea pigs.
Licorice Root also contains a flavonoid. Flavonoids are a natural substance from in plants. Flavonoids also have antioxidant properties.
Another component, glycyrrhizin, has been found to have anti-inflammatory and antimicrobial benefits. This may make licorice root extract effective at treating acne. However, more research is needed to support this.
Liquiritin is one of the flavone compounds found in licorice. It has been found to help lighten skin by preventing tyrosinase from reacting with tyrosine. When the two react, protein is converted to melanin. Melanin is the substance in your body that gives your features pigmentation.
Learn more about Glycyrrhiza Glabra Root ExtractMethyl Trimethicone is a type of silicone. It is a solvent and emulsifier.
Solvents are used to keep ingredients together in a product. They can help dissolve ingredients to stable bases or help evenly distribute ingredients throughout the product.
Emulsifiers help stabilize a product. It does this by preventing certain ingredients from separating.
Methyl Trimethicone does not get absorbed into the skin.
Learn more about Methyl TrimethiconeCarthamus tinctorius seed oil comes from safflower, one of humanity's oldest crops.
Safflower seed oil contains a high percentage of linoleic acid and oleic acid. It also contains Vitamin E. These three components are effective moisturizers.
Vitamin E helps nourish your skin's lipid barrier. It is also a potent antioxidant. Antioxidants help fight free-radical molecules, or unstable molecules that may damage your skin cells.
Thoughout history, safflower has been used for dying fabrics and in food as a saffron substitute.
Learn more about Carthamus Tinctorius Seed OilCamellia Japonica Seed Oil comes from the Japanese Camellia plant. This plant is native to East Asia and known as "Tsubaki" in Japanese.
Camellia Japonica Seed Oil is rich in oleic acid. This makes it a great emollient. Emollients help soften and soothe the skin by forming a barrier. This barrier traps moisture within, keeping your skin hydated.
Daucus Carota Sativa Root Extract comes from the root commonly known as carrot (the orange kind we eat!).
This extract contains beta-carotene, a pigment responsible for giving plants the orange color. Beta-carotene is a potent antioxidant. Antioxidants may help reduce the signs of aging.
Beta-carotene is the reason we turn orange if we eat too many carrots.
It should be noted coming into contact with the leaves of wild carrots can cause skin irritation. The sap causes phytophotodermatitis, or sensitivity when the sap comes in contact with sunlight.
This ingredient is created using the edible parts of the carrot.
Learn more about Daucus Carota Sativa Root ExtractBeta-Carotene is a carotenoid. It is an antioxidant that converts to Vitamin A. Antioxidants help fight free-radicals. Free-radicals are molecules that may damage your skin cells, such as pollution.
It gives plants the red, orange, and yellow color. Some foods with Beta-Carotene include sweet potatoes, carrots, apricots, and cantaloupe.
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When to use
We've created a guide with info on when you should use COSRX The Vitamin C 23 Serum. We've also included some recommended products to use it with, as well as some routine inspiration!
Read our guide on when to use The Vitamin C 23 Serum ->We're dedicated to providing you with the most up-to-date and science-backed ingredient info out there.
The data we've presented on this page has been verified by a member of the SkinSort Team.
Read more about usTop Reviews
View all 7(Started Dec 2023) I would say that this is a great high concentration serum that was gentle enough on my sensitive skin. By March 2024, I managed to get through two bottles and I can't say there have been any notable changes, which is...
(Started Dec 2023) I would say that this is a great high concentration serum that was gentle enough on my sensitive skin. By March 2024, I managed to get through two bottles and I can't say there have been any notable changes, which is disappointing considering how expensive this is. My main complaint is that I found the scent of this formulation to be very strong with initial application, but it dissipates over time and another complaint is it leaves my face feeling very sticky for a serum (As it is not the last part of my routine, my moisturizing step usually resolves this).
I didn't like the consistency of this serum at all.
It felt like I was putting oil to my face, but since I always use the whole product to see results this did nothing to me other than feeling uncomfortable.
I didn't like the consistency of this serum at all.
It felt like I was putting oil to my face, but since I always use the whole product to see results this did nothing to me other than feeling uncomfortable.
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