COSRX The Vitamin C 13 Serum Review

COSRX The Vitamin C 13 Serum
3.8
/ 10
Moisturizing
7.3 Humectancy icon Humectancy
0.4 Occlusivity icon Occlusivity
2.9Anti-wrinkle icon/ 10
Anti-wrinkle
Rich
in Antioxidants
Ingredients

COSRX The Vitamin C 13 Serum Ingredients

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Full Ingredient List (INCI):

Water, Ascorbic Acid, Butylene Glycol, Dipropylene Glycol, Tromethamine, Panthenol, Acetyl Glucosamine, Caffeine, Sodium Hyaluronate, Sodium Sulfite, Disodium EDTA, Glutathione, Adenosine, Gardenia Florida Fruit Extract, Allantoin, Dextrin, Squalane, Tocotrienols, Tocopherol, Elaeis Guineensis (Palm) Oil, Arginine, Niacinamide, Pentylene Glycol, Glycyrrhiza Glabra (Licorice) Root Extract
Review

Does COSRX The Vitamin C 13 Serum Work?

 
According to CreamScan's analysis of the ingredient list, here’s what COSRX The Vitamin C 13 Serum has to offer:
 
✅ Light moisturizing. It has a moisturizing rating of 3.8 out of 10.
✅ Modest anti-wrinkle efficacy: COSRX The Vitamin C 13 Serum has an anti-wrinkle rating of 2.9 out of 10 so you may expect some, although limited, effect on wrinkles.
✅ Antioxidant protection

  

Key Benefits of COSRX The Vitamin C 13 Serum

 
These are the key benefits you can expect from using COSRX The Vitamin C 13 Serum:
 

🔵 Lightweight Moisturizer Well-Suited for Oily Skin

According to CreamScan analysis, COSRX The Vitamin C 13 Serum is lightly moisturizing, with a moisturizing rating of 3.8 out of 10.

Is it more humectant or occlusive? Significantly more humectant. It has a low occlusivity of 0.4 out of 10 and a high humectancy of 7.3 out of 10, primarily due to the high content of Butylene Glycol (est. ≈4.0%).

This humectant-rich product, when used alone as a moisturizer, is well-suited for oily skin, providing moderate hydration in a lightweight, fast-absorbing formula with a minimal amount of occlusive ingredients.

It can also be a good option for people with normal skin who prefer lightweight moisturizers.

💧 A Humectant Enhancement for Any Skincare Routine

But it’s not limited to oily skin - such a humectant enhancement will also positively contribute to the moisturizing efficacy of any skincare routine when used as a step before applying the main moisturizer. This type of formulation is typically used in serums, where a light, fast-absorbing texture is key.

Please refer to the Ratings section below for details of the moisturizing rating calculation.

🟣 Modest Anti-Wrinkle Efficacy

According to CreamScan analysis, COSRX The Vitamin C 13 Serum has a modest level of anti-wrinkle efficacy, rated 2.9 out of 10.

It contains 2 active ingredients with proven anti-wrinkle efficacy:

1️⃣ Ascorbic Acid (est. ≈13.0%),
 or Vitamin C, a popular ingredient, yet with moderate anti-wrinkle efficacy, as confirmed by a single clinical study involving 20 participants (Humbert et al.). This study showed that a cream with a relatively high concentration of 5% ascorbic acid reduced the average wrinkle depth by 7% after 6 months of use, compared to a vehicle (the same formulation without ascorbic acid).
 
2️⃣ Niacinamide (est. ≈0.3%),
 one of the most effective and well-researched anti-wrinkle ingredients. A clinical study involving 30 participants (Kawada et al.) confirmed that a cream with 4% niacinamide reduced the average depth of wrinkles around the eyes by 9% after 8 weeks of use, compared to a vehicle (the same formulation without niacinamide).
 
Among others, COSRX The Vitamin C 13 Serum also contains some ingredients marketed often as effective in reducing wrinkles, specifically Acetyl Glucosamine, Caffeine, and Adenosine. However, the studies supporting the anti-wrinkle claims of these ingredients provide insufficient evidence of efficacy according to CreamScan Research Evaluation Standards.
 
While this does not categorically rule out the possibility that these ingredients may reduce wrinkles, their efficacy is not supported by convincing, vehicle-controlled, double-blind clinical studies - at least none that were available to the CreamScan team at the time of publication.
 
Therefore, these ingredients do not contribute to the anti-wrinkle rating.
 
📌 Moisturizers, when used regularly, are proven to prevent wrinkle formation and even reduce existing wrinkles. Therefore, this product, like any other moisturizer, can deliver some additional anti-wrinkle effects through its moisturizing action.
 

Please refer to the Ratings section below for details of the anti-wrinkle rating calculation.

🍀 Rich in Skin-Protecting Antioxidants

We estimate that COSRX The Vitamin C 13 Serum is rich (> 3%) in antioxidants, specifically Ascorbic Acid (est. ≈13.0%).

A key benefit of antioxidants is their ability to reduce oxidative stress caused by free radicals and therefore prevent accelerated skin aging. Studies also show that antioxidants can protect against environmental damage such as UV radiation and pollution, and help reduce inflammation and skin redness.

📌 Please note that this is not a complete list of benefits. We are in the process of enhancing our model to incorporate anti-pigmentation, exfoliation and anti-acne ratings.

Pros & Cons of COSRX The Vitamin C 13 Serum

 
Here’s an overview of the pros and cons of COSRX The Vitamin C 13 Serum to help you decide if it’s the right choice for your skincare routine:
 

🟩 Pros:

✅ When used alone: Provides humectant-rich moisturizing well-suited for oily skin
✅ As part of a routine: A humectant moisturizing enhancement, beneficial for any skin type
✅ Lightweight texture
Offers modest anti-wrinkle efficacy
✅ Rich in antioxidants that combat oxidative stress associated with accelerated skin aging and defend against environmental damage
 

⭕ Cons: 

✅ We couldn't find any
   

Summary: COSRX The Vitamin C 13 Serum

 
Based on the ingredient list analysis, CreamScan AI suggests that COSRX The Vitamin C 13 Serum
, when used alone, delivers lightweight, humectant-rich moisturizing that is well-suited for oily skin. As part of a moisturizing routine, it provides a humectant enhancement, beneficial for all skin types.
 
COSRX The Vitamin C 13 Serum contains ingredients with proven evidence of anti-wrinkle efficacy that may provide a modest anti-wrinkle effect. As a result, you can expect a positive, though not very significant, impact on wrinkles.
 
With its high antioxidant content, COSRX The Vitamin C 13 Serum helps protect against free radical damage and offers multiple benefits for all skin types, including preventing premature aging, defending against environmental damage, and calming inflammation.
 
📌 Fact check. At CreamScan, we are committed to accuracy and fairness. If you spot any errors or something that doesn’t seem right, please click here to let us know. We regularly update the ingredient lists and monitor the latest research on ingredient efficacy to ensure that our information remains as complete and precise as possible. The information provided here is for informational purposes only and does not substitute professional advice. We do not guarantee the efficacy or safety of any product, as individual results may vary.

 

Ingredient Breakdown

Est. % Ingredient Origin Functions
70
13
4
3
2
1.5
1.3
1
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
Est. %
Water
Function:
Origin:
Ascorbic Acid
Function:
Origin:
Butylene Glycol
Function:
Origin:
Dipropylene Glycol
Function:
Origin:
Tromethamine
Function:
Origin:
Panthenol
Function:
Origin:
Acetyl Glucosamine
Function:
Origin:
Caffeine
Function:
Origin:
Sodium Hyaluronate
Function:
Origin:
Sodium Sulfite
Function:
Origin:
Disodium EDTA
Function:
Origin:
Glutathione
Function:
Origin:
Adenosine
Function:
Origin:
Gardenia Florida Fruit Extract
Function:
Origin:
Allantoin
Function:
Origin:
Dextrin
Function:
Origin:
Squalane
Function:
Origin:
Tocotrienols
Function:
Origin:
Tocopherol
Function:
Origin:
Elaeis Guineensis (Palm) Oil
Function:
Origin:
Arginine
Function:
Origin:
Niacinamide
Function:
Origin:
Pentylene Glycol
Function:
Origin:
Glycyrrhiza Glabra (Licorice) Root Extract
Function:
Origin:

Ratings

All humectants
7.3
4
1.5
0.3
0.3
0.3
0.3
0.3
0.3
Benchmark
10
All occlusives
0.9
0.3
0.3
0.3
Benchmark
20
Moisturizing rating
3.8
Ingredient Est. % Benchmark Raiting
Humectancy All humectants 7.3 10
7.3
4
1.5
0.3
0.3
0.3
0.3
0.3
0.3
Occlusivity All occlusives 0.9 20
0.4
0.3
0.3
0.3
Moisturizing rating
3.8
Ingredient Est. % Benchmark Humectancy
4
1.5
0.3
0.3
0.3
0.3
0.3
0.3
All humectants 7.3 10
7.3
All humectants
7.3
4
1.5
0.3
0.3
0.3
0.3
0.3
0.3
Benchmark
10
Ingredient Est. % Benchmark Occlusivity
0.3
0.3
0.3
All occlusives 0.9 20
0.4
All occlusives
0.9
0.3
0.3
0.3
Benchmark
20
Ingredient
Ingredient anti-wrinkle power
when present at, %
in this formula est. %
Rating
2.5 /10 5 13 2.5
6 /10 4 0.3 0.4
n/a
- 1.3 -
n/a
- 1 -
n/a
- 0.3 -
Total
2.9
Ascorbic Acid
2.5
Ingredient anti-wrinkle power
2.5 /10
when present at, %
5
in this formula, est. %
13
Niacinamide
0.4
Ingredient anti-wrinkle power
6 /10
when present at, %
4
in this formula, est. %
0.3
Acetyl Glucosamine
-
Ingredient anti-wrinkle power
n/a
when present at, %
-
in this formula, est. %
1.3
Caffeine
-
Ingredient anti-wrinkle power
n/a
when present at, %
-
in this formula, est. %
1
Adenosine
-
Ingredient anti-wrinkle power
n/a
when present at, %
-
in this formula, est. %
0.3
Anti-wrinkle rating
2.9
Ingredient Est. % Benchmark
Rich in Antioxidants
13
1
0.3
0.3
0.3
0.3
0.3
0.3
All antioxidants 15.8 3 Rich in antioxidants
All antioxidants
15.8
Ascorbic Acid
13
Caffeine
1
Niacinamide
0.3
Sodium Hyaluronate
0.3
Sodium Sulfite
0.3
Glutathione
0.3
Tocopherol
0.3
Glycyrrhiza Glabra (Licorice) Root Extract
0.3
Benchmark
3
Ingredient Est. % Benchmark
Rich in Soothing
1.5
0.3
0.3
0.3
All soothing 2.4 5 No
All soothing
2.4
1.5
0.3
0.3
0.3
Benchmark
5

Ingredients explained

Water
Est. %70
Function
Origin
WaterThe most used ingredient in skincare. Its concentration defines the product texture: rich creams may have about 50% of water while a light jelly about 90%. Water doesn’t moisturize the skin by itself and is used in skincare as a solvent for other ingredients.
Ascorbic Acid
Est. %13
Function
Origin
Ascorbic Acid

Also known as vitamin C, this multi-benefit ingredient has proven anti-wrinkle, antioxidant, and anti-pigmentation efficacy. It degrades easily when exposed to air and light, so it requires proper packaging to maintain its stability.

Butylene Glycol
Est. %4
Function
Origin
Butylene Glycol

A clear, colorless liquid humectant that draws moisture to the skin. The humectancy of butylene glycol, owed to its two hydroxyl groups, is quite considerable, although not as powerful as glycerin, which contains three hydroxyl groups.

Dipropylene Glycol
Est. %3
Function
Origin
Dipropylene GlycolA clear, colorless liquid that has several uses. One of its main functions is as a solvent. Dipropylene glycol is also used to reduce the thickness of skincare products.
Tromethamine
Est. %2
Function
Origin
TromethamineAn ingredient based on amino acids that is commonly used as a pH adjuster. It has a high pH, which means that it is basic (alkaline), so adding tromethamine to a skincare product will increase its overall pH level.
Panthenol
Est. %1.5
Function
Origin
PanthenolA popular soothing and moisturizing derivative of vitamin B5. Panthenol is particularly beneficial for dry, flaking, burned, or damaged skin. It is used to alleviate the symptoms of a rash, dermatitis, eczema, chapped lips, and sunburn.
Acetyl Glucosamine
Est. %1.3
Function
Origin
Acetyl GlucosamineA body-natural amino-saccharide used in skincare as an anti-pigment ingredient. Some other benefits of acetyl glucosamine include decreased skin flakiness, improved wound healing, and even a slight reduction in facial wrinkles.
Caffeine
Est. %1
Function
Origin
CaffeineAn antioxidant compound that is obtained from coffee and tea leaves. It increases the microcirculation of blood in the skin and is claimed to be able to reduce the appearance of orange peel skin (although the research is lacking).
Sodium Hyaluronate
Est. %0.3
Function
Origin
Sodium Hyaluronate

A sodium salt of famous hyaluronic acid. A potent humectant that hydrates the skin, supports collagen function, and fills out small wrinkles. Sodium hyaluronate also offers soothing and antioxidant properties.

Sodium Sulfite
Est. %0.3
Function
Origin
Sodium SulfiteAn inorganic salt that defends against oxidation.
Disodium EDTA
Est. %0.3
Function
Origin
Disodium EDTAA synthetic chelator that helps to maintain the look and smell of a product by 'locking up' troublesome metal ions.
Glutathione
Est. %0.3
Function
Origin
GlutathioneA naturally occurring tripeptide that combats free radicals and acts as a reducing agent.
Adenosine
Est. %0.3
Function
Origin
Adenosine

A key molecule responsible for energy transportation, signaling, and enzyme activity. Adenosine is a popular anti-wrinkle ingredient, however, the key study about its anti-wrinkle efficacy (1) does not meet CreamScan Research Evaluation Standards as it is not double-blind.

Gardenia Florida Fruit Extract
Est. %0.3
Function
Origin
Gardenia Florida Fruit ExtractDerived from the dark orange fruits of a Chinese flowering shrub called Gardenia florida, this extract acts as a yellow pigment.
Allantoin
Est. %0.3
Function
Origin
AllantoinA fluffy, white powder that acts as a humectant due to its water-loving chemistry and as an exfoliant that helps to remove dead skin cells. It has also been shown to be very soothing to irritated and inflamed skin.
Dextrin
Est. %0.3
Function
Origin
DextrinA partially hydrolyzed potato starch, most commonly used as a viscosity controlling and binding agent. When dispersed into water, it can create textures ranging from a thick paste to a soft gel.
Squalane
Est. %0.3
Function
Origin
SqualaneAn occlusive moisturizing and emollient compound that forms part of the skin’s sebum. The main source of squalane had always been shark liver. Now, however, it is manufactured synthetically or derived from plant oils, such as olive and peanut oil.
Tocotrienols
Est. %0.3
Function
Origin
Tocotrienols
Tocopherol
Est. %0.3
Function
Origin
Tocopherol

Simply another name for vitamin E. Tocopherol is a fantastic ingredient and especially beneficial for dry and inflamed skin. It has occlusive moisturizing, emollient, antioxidant, and photoprotective properties.

Elaeis Guineensis (Palm) Oil
Est. %0.3
Function
Origin
Elaeis Guineensis (Palm) OilA fatty oil expressed from the pulp of the oil palm fruits. It is mostly composed of occlusive and emollient saturated fatty acids. The unrefined oil has a large amount of antioxidant carotenoids.
Arginine
Est. %0.3
Function
Origin
ArginineA humectant amino acid used to attract water to the skin’s surface. It is a part of the skin's Natural Moisturizing Factor, a mixture of various compounds that keeps the skin’s surface well hydrated. Arginine can also be used as a pH adjuster.
Niacinamide
Est. %0.3
Function
Origin
Niacinamide

Also known as vitamin B3, this ingredient is a true superstar with confirmed moisturizing, anti-acne, hyperpigmentation, and antioxidant benefits. Two studies confirm its significant anti-wrinkle efficacy.

Pentylene Glycol
Est. %0.3
Function
Origin
Pentylene Glycol

A naturally or synthetically derived preservative that exhibits effective antifungal and antibacterial traits. It also acts as a booster for more traditional preservatives. Pentylene glycol can also serve as a moisturizing humectant and solvent.

Glycyrrhiza Glabra (Licorice) Root Extract
Est. %0.3
Function
Origin
Glycyrrhiza Glabra (Licorice) Root ExtractAn extract from the licorice root. It contains a well-researched anti-inflammatory compound called glycyrrhizin that can reduce inflammation. Licorice root extract is also used for its powerful antioxidant effects and ability to treat pigmentation.