Compare Products: The Niacinamide 15 Serum vs Niacinamide Oil Control Serum

COSRX

The Niacinamide 15 Serum

Mid-range15%
$25 / 20ml — $1.25/ml
The Inkey List

Niacinamide Oil Control Serum

Budget10%
$10.5 / 30ml — $0.35/ml

Who It's Designed For

COSRX
  • Oily and acne-prone skin seeking serious oil control
  • Post-acne marks and hyperpigmentation
  • Enlarged pores and textured skin
  • Users ready to step up from 10% to higher-strength niacinamide
  • Those who prefer minimal-ingredient formulas
The Inkey List
  • Oily and combination skin seeking oil control
  • Acne-prone skin wanting to reduce blemishes
  • Enlarged pores and uneven texture
  • Those sensitive to zinc who want a niacinamide serum
  • Niacinamide beginners looking for a gentle entry point

Key Ingredients

COSRX

Niacinamide (15%), Acetyl Glucosamine (2%), Zinc PCA (1%), Allantoin (0.1%)

The Inkey List

Niacinamide (10%), Hyaluronic Acid (1%)

Product Composition

28% similarity (8 ingredients in common)

Shared Ingredients
waterniacinamidebutylene glycolxanthan gumallantoinethylhexylglycerinsodium phytatecitric acid
Only in COSRX (8)
pentylene glycolacetyl glucosamine12-hexanediolzinc pcatrehalosepullulantocopherol
Only in The Inkey List (13)
propanediolphenoxyethanolhydroxyethylcellulosephospholipidssqualaneglycine soja (soybean) oilpolysorbate 60panthenolglycolipidsleuconostoc/radish root ferment filtratesorbitan isostearateglycine soja (soybean) sterolshyaluronic acid

User Feedback Patterns

COSRX
Oil control standout

Users consistently report significant reduction in daytime oil and shine. Many describe it as the best niacinamide serum they have tried for sebum control.

Lightweight texture praised

Unlike some high-concentration serums, this absorbs quickly without tackiness or residue. Layers well under other products.

Small bottle concern

The 20ml size (vs. 30ml standard) is a common gripe, especially given the price point.

Pore improvement takes time

Users report visible pore improvement around the 3-4 week mark with consistent twice-daily use.

The Inkey List
No pilling

Multiple users note this formula does not ball up under other products or makeup, unlike some competing niacinamide serums.

More hydrating than expected

Users with dry or combination skin report this feels more hydrating than pure niacinamide serums with zinc, likely due to the squalane, HA, and lack of zinc.

Packaging frustrations

The squeeze bottle with press-down cap makes it difficult to control how much product dispenses. Some users report buildup around the opening.

Visible pore improvement

Consistent feedback about reduced pore appearance within 2-4 weeks of daily use.

Which Should You Buy?

The Inkey List Niacinamide Oil Control Serum offers great value at a lower price point. COSRX The Niacinamide 15 Serum may be worth the premium if you want Niacinamide (15%).

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