Versus

Eight Saints Original Cin Niacinamide 10% Serum Versus COSRX The Niacinamide 15 Serum

Serum
Serum
American Brand United States
Korean Brand South Korea

Updated on April 01, 2025

Overview

What they are

These products are both cruelty-free, fungal acne (malassezia) safe, and reef safe serums. They have a total of 4 ingredients in common

Cool Features

They both contain niacinamide

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 and dark spots

Free From

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

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

Key Ingredients

Benefits

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
Smoothing

Niacinamide 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 Niacinamide
Humectant, Skin Conditioning

Zinc PCA (or "zinc salt") differs slightly from zinc itself. PCA stands for pyrrolidone carboxylic acid. However, Zinc PCA comes from zinc.

It can help reduce redness, regulate sebum, and promote the general healing process of the skin.

Zinc PCA tends to be especially useful for those with oily, acne-prone skin. It's certainly an ingredient worth trying out!

Learn more about Zinc PCA
Emulsifying, Emulsion Stabilising, Gel Forming

Xanthan gum is used as a stabilizer and thickener within cosmetic products. It helps give products a sticky, thick feeling - preventing them from being too runny.

On the technical side of things, xanthan gum is a polysaccharide - a combination consisting of multiple sugar molecules bonded together.

Xanthan gum is a pretty common and great ingredient. It is a natural, non-toxic, non-irritating ingredient that is also commonly used in food products.

Learn more about Xanthan Gum

When to use

9 Routines
33% use in am
67% use in pm
89% use every day
743 Routines
45% use in am
55% use in pm
91% use every day
When to use See routines that use it ->

Reviews

Here's what our community thinks

Eight Saints Original Cin Niacinamide 10% Serum 9 ingredients

Original Cin Niacinamide 10% Serum hasn't been rated yet.
Rate it now

COSRX The Niacinamide 15 Serum 15 ingredients

3.3 /5
from 12 ratings
Irritating (5) No Scent (5) Doesn't Work (3)
glittertimes's avatar

Ryan 🩷

7 months ago
Review

warning!!! this can be SO irritating *if you use it wrong*

do not use with
-ahas
-bhas
-vit c
-other niacinamide products
-start on dry skin first as wet skin absorbs more

tip: sandwich it. i put a little centella ampoule before and after this serum to prevent irritation. if used properly, this serum is a life changer! i struggle with closed comedones and acne scars and this helped Show more

#irritating
#absorbs well
#no scent
#works well
ChienYun_CY's avatar

Chien Yun Ang

1 year ago
Review

HG acne scar serum
Initially, this serum had helped fade away most of my old acne scars. After while, I thought it didn't do anything more for my new acne growth. So I ditched this serum for about 3 months and tried other new niacinamide products. I REGRET it. Soon after, I got more and more whiteheads and acne. My skin texture becomes uneven and dry. The new acne scars couldn't fade away at all. Show more