COSRX - The Niacinamide 15 Serum [20ml]

COSRX The Niacinamide 15 Serum is a high-concentration take on one of skincare's most reliable ingredients — and the concentration is the thing to think about, because with niacinamide more is not straightforwardly better.

The Niacinamide 15 Serum at a glance

Why 15% is a deliberate choice, not simply a better one

Niacinamide is one of the genuinely well-supported ingredients available without a prescription. It helps regulate oil, improves the look of pore size, supports barrier function, and reduces post-inflammatory marks and redness. It is also usually very well tolerated. Little of that needs qualifying.

The concentration does. Most of the research behind those benefits used somewhere in the region of 2% to 5%. Going far above that has not been shown to deliver proportionally more, while irritation reports — flushing, tingling, redness — rise noticeably at 10% and above. A meaningful number of people who say niacinamide does not agree with them were using a high-percentage product.

So treat 15% as a specialist option rather than a starting point. If you already use niacinamide comfortably and want a stronger version, this is a reasonable step up. If you have never used it, a lower percentage will very likely give you the same results with less risk of a reaction — and if you react to this one, the sensible conclusion is that the concentration was wrong for you, not the ingredient.

Introduce it slowly: every other day at first, and on part of the face before all of it.

How to use it

1. Patch test first on a small area for a few days.
2. Start every other day, applying a few drops after toner.
3. Build to daily only if your skin stays comfortable.
4. Follow with moisturiser, and sunscreen every morning.

Browse the full COSRX range at EmartGCC, or the Korean serums collection.

Frequently asked questions

Is 15% better than a lower percentage?

Not reliably. Most evidence for niacinamide's benefits sits around 2% to 5%, while irritation becomes more common above 10%. Higher is stronger, not automatically more effective.

My skin went red and tingly. What happened?

That is the most common reaction to high-percentage niacinamide. Reduce frequency, or switch to a lower concentration — the ingredient is likely fine for you, the strength is not.

Can I use niacinamide with vitamin C?

Yes. The old warning against combining them came from lab conditions that do not reflect how modern products are formulated. Using both is fine; if you prefer, put one in the morning and one at night.

Will it shrink my pores?

Pore size is largely genetic and cannot be permanently changed. Niacinamide reduces how visible pores look by regulating oil and improving skin texture, which is a real but cosmetic effect.

Does it fade dark spots?

It helps with post-acne marks and general unevenness. For established sun spots, a dedicated brightening active such as the Alpha-Arbutin 2 serum is more targeted — and both need daily sunscreen.

Can I use it with retinol or acids?

Yes, though stacking a high-strength niacinamide with other actives raises irritation risk. Introduce one product at a time and consider alternating nights.

How long until I see results?

Oil control and redness often improve within two to four weeks. Marks and tone take eight to twelve weeks.

Buying COSRX in Kuwait

EmartGCC supplies 100% original COSRX with free standard home delivery across Kuwait, usually next day. Areas beyond Fahaheel and Jahra carry a 3 KD delivery surcharge. Cash on delivery is available, and unopened items can be returned within 14 days.