Updated on August 23, 2024
Overview
What they are
These products are both reef safe . 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, 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
COSRX The Niacinamide 15 Serum 15 ingredients
Slurp Niacid 18 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
COSRX The Niacinamide 15 Serum 15 ingredients
Slurp Niacid 18 ingredients
Key Ingredients
Benefits
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Ingredients Explained
These ingredients are found in both products.
Ingredients higher up in an ingredient list are typically present in a larger amount.
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 NiacinamideButylene 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 Glycol1,2-Hexanediol is a synthetic liquid and another multi-functional powerhouse.
It is a:
- Humectant, drawing moisture into the skin
- Emollient, helping to soften skin
- Solvent, dispersing and stabilizing formulas
- Preservative booster, enhancing the antimicrobial activity of other preservatives
Ethylhexylglycerin (we can't pronounce this either) is commonly used as a preservative and skin softener. It is derived from glyceryl.
You might see Ethylhexylglycerin often paired with other preservatives such as phenoxyethanol. Ethylhexylglycerin has been found to increase the effectiveness of these other preservatives.
Ingredient Ratings
Here's what our community thinks of the ingredients in these products.
When to use
COSRX The Niacinamide 15 Serum 15 ingredients
Slurp Niacid 18 ingredients


Reviews
Here's what our community thinks
COSRX The Niacinamide 15 Serum 15 ingredients
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
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
Slurp Niacid 18 ingredients
TL;DR: Makes me oily and can sting a bit. Breaks me out SOMETIMES, but helped with scarring.
This is the ONLY Slurp product I don't 100% love. Sometimes it breaks me out into cysts, sometimes it doesn't. I had good results with some acne scarring on it, but it also made me feel a bit oily. It can sting on a compromised skin barrier for a split second, but it's never overly irritating. Because I Show more
UPDATE: it contains butylene glycol! If you use actives that affect your skin barrier, please restrain from using it. Also many Korean products use it. Hence layering it with other products might cause irritation!
Funny enough, that’s actually the only serum by Slurp that I do like. It absorbs fast and I do feel like my skin feels better afterwards. So I do think it helps the skin barrier. Show more