Name: The Niacinamide 15 Serum
Brand: COSRX
Rating: 4.11 (9 reviews)

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This is a Health Functional Food certified by the Ministry of Food and Drug Safety (MFDS) of Korea, designed to help maintain and improve your health.

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Tell us about what you liked - texture, results, skin type, etc

Tell us what didn’t work - texture, skin reaction, or why you wouldn’t recommend it

코스알엑스

The Niacinamide 15 Serum

Absorbs Well

Slippery

Feels Harsh on Skin

Oily

Unsatisfactory Scent

Causes Breakouts

Not Sticky

Lightweight

Improves Complexion

Manages Pores

Improves Skin Tone

Refreshing

Improves Skin Texture

I recommend applying a small amount to your face when your toner is about 90% absorbed, and blending it together with the toner!

Don't use it with heavy-textured products~
On days when you use this, it might be enough on its own
(excluding things like eye cream)

I'd like to include texture shots or other usage photos, but it's too much hassle..
Anyway, for someone with very oily skin, it's not heavy when used in small amounts, and it's effective for blemish prevention, skin barrier improvement, complexion enhancement, and skin texture refinement. It seems like a product worth using without any downsides :)

Since it's not heavy for oily skin (when used in small amounts),
it probably won't be heavy for other skin types either,

Even though I don't have blemishes anymore, my skin is still quite sensitive,
but there was absolutely no irritation!
I really, really like it :)

The packaging also allows for easy control of the amount dispensed, and honestly, even if I try, I can't find any cons!!

Wow... this is truly a holy grail product!

I've been trying for years to achieve plump, pore-tightening, and blemish-free oily skin without expensive treatments or procedures. It's been quite a journey!

But honestly, until last year and early spring, I was so stressed about the bumpy texture and sebum buildup. After revamping my summer skincare routine, I'm now living with the best skin of my life!

For those with blemish-prone skin who might be hesitant to try new products, I'll briefly describe my skin situation:

My skin is currently in great condition, but it's still sensitive. I originally had combination dehydrated skin that was extremely oily.

While I've managed to control blemishes with other products, I'm now focusing on tightening pores and improving elasticity. And this product is a game-changer!

∎ Why I bought it, its purpose & effects!

First, I've seen great results from the niacinamide in an EGF serum (from Sidmool) for pore tightening, skin elasticity, and fading blemish marks and dark spots. I've consistently invested in that expensive product (around $39 for 11ml?).

It was the most effective product for me, even though it doesn't contain a ton of EGF.

I thought niacinamide might be contributing significantly to the effects. When I saw this product on Director Pi's channel, I decided to give it a try.
(I bought it in early July for about $11 during a sale event. I believe it's usually around $19 on sale now. I received it on 7/20 through pre-order shipping.)

And sure enough, the niacinamide effect was spot on!

✅Pore tightening!! (An effect I noticed since using the Sidmool EGF ampoule)
✅Smooth skin texture, and as someone with oily, large-pored skin, I'm surprised every morning by how beautifully my skin glows...
✅Director Pi mentioned it's effective for blemishes too. I rarely get breakouts these days, but even after heavy makeup and water activities, I used this product before bed and woke up with zero new blemishes!
✅Recently, I haven't had any redness or irritation (thanks to other products and long-term care), but even so, the morning after using this product, I don't get any surface redness easily from exfoliation or anything else!

∎ Unique advantages of this product!

While niacinamide in any product would be good, Director Pi introduced this as having an excellent ingredient composition and high concentration. At this price point, I think I'll stick to this product!

I'm so satisfied with both the price and the user experience that I'm not even curious about other products! I plan to keep using the Sidmool EGF ampoule for its excellent scar improvement, but this product offers:

✅Skin texture refinement
✅Slight brightening effect, improved complexion, dark circle and dull skin tone improvement (even in summer!)
✅Feels like it's improving the skin barrier too, my skin feels really comfortable and plump!

Because of these effects, I plan to keep using it consistently for daily skin barrier/pore/complexion improvement.

∎ How does it feel to use?

So, what about the user experience, which I mentioned as another advantage of this product besides its price?

First, as someone with very oily skin, even in my summer skincare routine, I only use toner and cream in the morning, skipping all ampoules and serums. I incorporate various skincare products for treatment in the evening.
(Writing this in late July)

In the evening, if I apply too much of this, I thought it might feel heavy, so I only used a small amount. It turns out it's designed to be effective with just a small amount anyway!

I use two layers of watery toner lightly, and before the last layer of toner is completely dry, I apply a tiny amount of this product (about a quarter of my pinky nail) on each cheek and blend it in, layering it with the toner.

It absorbs well and spreads evenly. It has a concentrated, rich texture, so it works well when applied with the latter part of toner application.

Besides this, it's been so hot lately,
(I tend to keep my living space warm, usually 26-27°C)
so I don't use other heavy ampoules when sleeping.

My current summer night routine is just toner, this product, cream, spot treatment for blemish marks, and occasionally a pore-tightening fibro ampoule for my pore areas.

I use the expensive Sidmool EGF sparingly, just for small acne scars.

I think I'll use this as my main product for elasticity and complexion care from now on :)
The price seems really good too (based on the sale price.. I feel like there's a regular price, but the sale price might be constant?)

더 나이아신아마이드 15 세럼

Avoid applying on areas with wounds or dermatitis as it may cause a stinging sensation.

While it's fragrance-free, those with sensitive noses might perceive a slight saliva-like or odd scent.

Some might feel like it's sitting on top of the skin due to a slightly slippery sensation after application.

I wish the container was transparent so you could see how much product is left.

The texture is like flowing water with a slightly moisturizing feel, but not sticky. After application, there's a bit of an oily sensation on the skin's surface. Those with very oily skin might find this sufficient on its own in summer.

It could be great for people with dull complexions, dark circles, blemishes, small bumps, or uneven skin texture. As for the scent, I didn't pay much attention since I only used it at night or didn't apply it when going out. If you're concerned about your skin, it's probably better than products with lots of fragrances.

The niacinamide seemed to work well for me, showing some effectiveness except on areas with dermatitis. Of course, I avoid applying such products on inflamed areas like rashes or acne - for those, it's better to use ointments or prescribed medications from a dermatologist.

I used to have a yellowish complexion with bumpy skin and occasional acne. Since using this, whether it's due to my recent exercise routine or not, people have commented that my skin looks better. I've noticed my complexion brightening and my skin texture improving. At the very least, it doesn't seem to have any negative effects on my skin.

However, everyone's skin is different. I don't usually recommend or discourage products based solely on my experience. Whether positive or negative, consider others' reviews as reference, but you'll need to try it yourself to know for sure.

* Apparently, they've decided to renew the product.

It works better when used together with a toner and emulsion.

The watery consistency means it's not very moisturizing. Especially since it's recommended for nighttime use, it dries out quickly when the air conditioning is on. It claims to be a serum for blemish-prone skin, but I'm skeptical... It doesn't seem to help with mask-related blemishes at all.

Almost no scent, which is great for those sensitive to fragrances. The watery, light texture makes it feel weightless and easy to apply.

When you apply it before bed, your skin has a beautiful glow the next day.

As someone with extremely dry skin, I was really craving deep hydration. After consistently applying this, I feel like my skin is less dry on the inside. I use it before bed, and when I wake up in the morning, my skin feels incredibly supple. I think this is truly an excellent product.

Applying this after your toner and moisturizer seems to help it spread more evenly. I found that using it at night works better for me than in the morning!

While those who frequently use serums or ampoules might be able to control the application, others might find that the product's runny texture could lead to over-dispensing. However, I have no concerns regarding the ingredients!

I tried this product after receiving it through the Hwahae event. It feels a bit different from the typical hyaluronic acid products we're all familiar with. There's hardly any stickiness, and if you control the amount well, you can easily distribute the right quantity. It doesn't have a noticeable fragrance, and it gives your skin a refreshed feeling. I wish I had known about it sooner - I would have definitely bought it! I'm even more excited now that I hear it's being renewed.

Just buy a different line. It's right after my period when my skin should be at its best, but because of this, my skin isn't recovering and I'm going crazy.

Skin type: Very thin skin that develops small bumps if not cared for properly. Not quite sensitive, but reacts differently to certain functional cosmetics. Rarely get one or two inflamed spots, with some warmth and redness on the cheeks. Not acne, but visible red areas.

While it's supposed to brighten and niacinamide is said to help with blemishes, after using it twice daily for 3 days (6 times total), my redness and blemishes actually got worse. Started breaking out in places I usually don't. Honestly, I felt my skin reacting badly from day one, but I kept using it hoping it would improve. Now I'm super stressed.

Texture: It's very runny like water, but when you spread it, it suddenly becomes sticky and thick. Feels more like oil than water.

Scent: The smell is really strange. I'm not usually sensitive to scents and rarely complain, but this genuinely smells like white clay dissolved in water, like the kind I used to buy at stationery stores in elementary school. Can't apply it near my nose because the smell is too strong.

I feel like my face actually gets a bit brighter. It's like my complexion is slightly more radiant?

For those with oily skin, it might feel a bit rich. I'd recommend using it as part of your nighttime routine.

I absolutely loved how it doesn't feel sticky and leaves my skin feeling wonderfully moisturized! It seems to be fragrance-free, and when applied before foundation, it helps prevent the makeup from separating.

The dropper was a bit small, which was slightly inconvenient, and it felt like it dried up quickly

It's so lightweight! The texture flows like water without being sticky

Recommended for:
Blemish-prone skin and all skin types

-When using in the morning, be sure to apply sunscreen afterward

The dropper head is a bit short, making it slightly inconvenient to use. It feels particularly precarious when my hands are slippery - I worry I might drop it. It would be better if it were just a tad longer.

•Texture
Transparent and watery, with a fluid consistency

•Scent
Nearly fragrance-free

•Application
Non-irritating, absorbs well, and quickly sinks into the skin
Initially feels slightly tacky, but finishes with a fresh, non-greasy feel

•Effects
The most significant impact was on blemishes!
It calmed existing blemishes and prevented new ones, maintaining a clear complexion
Secondly, it greatly improved skin texture
Balances oil and moisture, reducing sebum production and oiliness
This multi-tasking serum tackles blemishes, sebum control, oil reduction, pores, dead skin cells, skin texture, and dark spots - isn't it the ultimate all-in-one solution?

•Ingredients
One of my key considerations when buying cosmetics is the ingredient list. My sensitive skin reacts quickly to harsh ingredients, but this product contains only 10 out of 20 caution ingredients and zero potential allergens, making it gentle and skin-friendly

•Highlights
I appreciate that the packaging is fully recyclable, with clear recycling instructions on the box
Lightning-fast delivery! Received it the very next day after ordering
Generous with samples, which was a nice touch

Korean Reviews

The Niacinamide 15 Serum

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