Compare Products: The Niacinamide 15 Serum vs Niacinamide 10% + Zinc 1% Serum

COSRX

The Niacinamide 15 Serum

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

Niacinamide 10% + Zinc 1% Serum

Budget10%
$6 / 30ml — $0.20/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 Ordinary
  • Oily and combination skin seeking oil control
  • Those who want a no-frills, high-potency niacinamide serum
  • Budget-conscious skincare users
  • People targeting enlarged pores and textural irregularities
  • Users building ingredient-focused routines

Key Ingredients

COSRX

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

The Ordinary

Niacinamide (10%), Zinc PCA (1%)

Product Composition

23% similarity (5 ingredients in common)

Shared Ingredients
waterpentylene glycolniacinamidezinc pcaxanthan gum
Only in COSRX (11)
butylene glycolacetyl glucosamine12-hexanedioltrehalosepullulanallantoinethylhexylglycerinsodium phytatecitric acidtocopherol
Only in The Ordinary (6)
dimethyl isosorbidetamarindus indica seed gumisoceteth-20ethoxydiglycolphenoxyethanolchlorphenesin

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 Ordinary
Holy grail for oily skin

Many users with oily skin report significant oil control and fewer breakouts. High repurchase rate in this demographic.

Pilling under other products

Commonly reported issue. Users recommend applying to damp skin or mixing with a hydrating serum to improve layering.

Tacky texture

The formula can feel sticky, especially if too much is applied. Most users adapt application technique over time.

Purging or breakouts

Some users report initial breakouts. Unclear whether this is purging, sensitivity, or coincidence. Most who push through report improvement.

Value for money

Almost universally praised for price-to-performance ratio. Common comment: 'can't believe this costs $6.'

Which Should You Buy?

The Ordinary Niacinamide 10% + Zinc 1% Serum offers great value at a lower price point. COSRX The Niacinamide 15 Serum may be worth the premium if you want Niacinamide (15%).

Premium Pick
Buy COSRX

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