Versus

COSRX The Vitamin C 13 Serum Versus Dr. Althea Gentle Vitamin C Serum

Serum
Serum
Korean Brand South Korea
Korean Brand South Korea

Updated on May 05, 2025

Overview

What they are

These products are both cruelty-free and reef safe serums. They have a total of 8 ingredients in common

Cool Features

They both contain niacinamide and Vitamin C

Suited For

They're both likely to be 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

They both do not contain any harsh alcohols, common allergens, parabens, silicones or sulfates

What's Inside

They both contain oils

We independently verify ingredients, and our claims are backed by peer-reviewed research. Spot a product that needs an update? Let us know.

Ingredient Info

Click any item below to learn more and see relevant ingredients

What's inside (and what isn't)

What's inside (and what isn't)

At a glance

Click on any of the items below to learn more

Key Ingredients

Benefits

Key Ingredients

Benefits

Ingredients Side-by-side

found in both products

Ingredients Explained

These ingredients are found in both products.

Ingredients higher up in an ingredient list are typically present in a larger amount.

Skin Conditioning, Solvent

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. If you see this, drink a glass of water. Stay hydrated!

Learn more about Water
Humectant, Masking, Skin Conditioning

Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:

Overall, Butylene Glycol is a safe and well-rounded ingredient that works well with other ingredients.

Though this ingredient works well with most skin types, some people with sensitive skin may experience a reaction such as allergic rashes, closed comedones, or itchiness.

Learn more about Butylene Glycol
Buffering, Masking

Tromethamine helps balance the pH and improve the texture of a product. It is synthetically created.

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 Tromethamine
Skin Conditioning

You might know this ingredient as Ethyl Ascorbic Acid, a more stable version of ascorbic acid.

Like other types of vitamin C, this ingredient has many benefits including reducing wrinkles, skin soothing, dark spot fading, and fighting against free radicals.

3-O-Ethyl Ascorbic Acid interferes with the process of skin darkening, helping to reduce hyperpigmentation. It also encourages the skin to produce more collagen.

Once applied, 3-O-Ethyl Ascorbic Acid is converted to Vitamin C deeper in the skin's layers. This process is slow but makes this ingredient more tolerable for skin.

The optimum pH range for this ingredient is 4 - 5.5

Learn more about 3-O-Ethyl Ascorbic Acid

Disodium 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 EDTA
Skin Conditioning

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 Adenosine
Skin Conditioning, Skin Protecting, Soothing

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 Allantoin
Smoothing

Niacinamide is a multitasking form of vitamin B3 that strengthens the skin barrier, reduces pores and dark spots, regulates oil, and improves signs of aging.

And the best part? It's gentle and well-tolerated by most skin types, including sensitive and reactive skin.

You might have heard of "niacin flush", or the reddening of skin that causes itchiness. Niacinamide has not been found to cause this.

In very rare cases, some individuals may not be able to tolerate niacinamide at all or experience an allergic reaction to it.

If you are experiencing flaking, irritation, and dryness with this ingredient, be sure to double check all your products as this ingredient can be found in all categories of skincare.

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.

When you apply niacinamide to your skin, your body converts it into nicotinamide adenine dinucleotide (NAD). NAD is an essential coenzyme that is already found in your cells as "fuel" and powers countless biological processes.

In your skin, NAD helps repair cell damage, produce new healthy cells, support collagen production, strengthen the skin barrier, and fight environmental stressors (like UV and pollution).

Our natural NAD levels start to decline with age, leading to slower skin repair, visible aging, and a weaker skin barrier. By providing your skin niacinamide, you're recharging your skin's NAD levels. This leads to stronger, healthier, and younger looking skin.

Another name for vitamin B3 is nicotinamide. This vitamin is water-soluble and our bodies don't store it. We obtain Vitamin B3 from either food or skincare. Meat, fish, wheat, yeast, and leafy greens contain vitamin B3.

The type of niacinamide used in skincare is synthetically created.

Learn more about Niacinamide

When to use

236 Routines
81% use in am
19% use in pm
90% use every day
When to use See routines that use it ->
384 Routines
79% use in am
21% use in pm
88% use every day
When to use See routines that use it ->

Reviews

Here's what our community thinks

COSRX The Vitamin C 13 Serum 25 ingredients

The Vitamin C 13 Serum hasn't been rated yet.
Rate it now

Dr. Althea Gentle Vitamin C Serum 20 ingredients

3.5 /5
from 10 ratings
Absorbs Well (7) No Scent (5) Light (5)
skincarewithmilan's avatar

Milan

10 months ago
Review

I’ve been using this product for the past couple of days and noticed that it’s making my skin break out with a few small closed comedones and pimples on my cheeks and nose. I highly doubt that my skin is purging since this serum contains ethyl ascorbic acid which is a more gentle alternative to L-ascorbic acid and vitamin C isn’t supposed to make the skin purge. I’m assuming the breakouts were Show more

#broke me out
#light
#absorbs well
#no scent
dajannamata's avatar

Dajanna Mata

8 months ago
Review

*This is a review for both Vitamin C Serums* This vitamin C serum for sensitive skin is a good product but didn’t have a good experience with the boosting vitamin C serum. Was applying the orange vitamin C serum for just 2-3 days straight and suddenly I started getting acne on my chin, forehead , which I never got acne on those places. Did not feel no irritation while applying the vitamin C , but Show more

#expensive
#broke me out
#light
#no scent