Versus

Protocol Vitamin C Superserum Versus COSRX The Vitamin C 23 Serum

Serum
Serum
American Brand United States
Korean Brand South Korea

Updated on June 28, 2024

Overview

What they are

These products are both cruelty-free and reef safe serums. They have a total of 3 ingredients in common

Cool Features

They both contain Vitamin C and Vitamin E

Suited For

They're both likely to be good for anti aging, dry skin, brightening skin, reducing pores, scar healing, dark spots and better texture

Free From

They both do not contain any common allergens, fragrances, parabens or sulfates

What's Inside

They both contain harsh alcohols

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

About this product

About this product

At a glance

Click on any of the items below to learn more

Key Ingredients

Benefits

Concerns

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

found in both products
The Vitamin C 23 Serum

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
Antioxidant, Buffering, Masking

Ascorbic 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 Acid
Antimicrobial, Astringent, Masking

Alcohol Denat. is an alcohol with a denaturant property. It is created by mixing ethanol with other additives.

This ingredient gets a bad rep because it is irritating and drying - mostly due to its astringent property. Astringents draw out natural oils in tissue, constricting pores and leaving your skin dried out.

However, alcohol denat. is not all that bad.

Due to its low molecular weight, alcohol denat. tends to evaporate quickly. One study on pig skin found half of applied alcohol evaporated in 10 seconds and less than 3% stayed on skin.

This also helps other ingredients become better absorbed upon application.

Studies are conflicted about whether this ingredient causes skin dehydration. One study from 2005 found adding emollients to propanol-based sanitizer decreased skin dryness and irritation. Another study found irritation only occurs if your skin is already damaged.

Small amounts of alcohol are generally tolerated by oily skin or people who live in humid environments.

The rule of thumb is if this alcohol is near the end of an ingredients list, it will probably not affect your skin much.

Also...

This ingredient has antimicrobial and solvent properties.

The antimicrobial property helps preserve products and increase their shelf life. As a solvent, it helps dissolve other ingredients.

Other types of astringent alcohols include:

Learn more about Alcohol Denat.

When to use

3 Routines
100% use in am
0% use in pm
100% use every day
599 Routines
76% use in am
24% use in pm
92% use every day
When to use See routines that use it ->

Reviews

Here's what our community thinks

Protocol Vitamin C Superserum 15 ingredients

Vitamin C Superserum hasn't been rated yet.
Rate it now

COSRX The Vitamin C 23 Serum 34 ingredients

3.7 /5
from 12 ratings
Works Well (5) Absorbs Well (3) Oily (3)
laila.21's avatar

Laila

1 year ago
Review

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.

#oily
#strong scent
#works well
ChienYun_CY's avatar

Chien Yun Ang

2 years ago
Review

Cured my acne scars
I had mix feelings when I first bought this as I read that the smell can be off-putting. But I am glad I bought it. My acne scars faded a lot more after 3 days of using it and saw great results in one week. It also didn't break me out despite containing alcohols and oils. It does sting a little on the first application but doesn't irritate my skin. The smell can be quite strong Show more