Compare Products: The Niacinamide 15 Serum vs Glass Skin Refining Serum

COSRX

The Niacinamide 15 Serum

Mid-range15%
$25 / 20ml — $1.25/ml
Peach & Lily

Glass Skin Refining Serum

Mid-range~2-5%
$39 / 40ml — $0.98/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
Peach & Lily
  • Sensitive or eczema-prone skin seeking gentle actives
  • Those wanting the 'glass skin' luminous hydration look
  • Users who prioritize fragrance-free, clean formulas
  • People new to niacinamide who want a lower concentration
  • K-beauty enthusiasts looking for a multi-benefit serum

Key Ingredients

COSRX

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

Peach & Lily

Niacinamide, Hyaluronic Acid (multiple types), Madecassoside, Peach Extract, Peptides

Product Composition

28% similarity (8 ingredients in common)

Shared Ingredients
waterniacinamidebutylene glycolacetyl glucosamine12-hexanediolethylhexylglycerinsodium phytate
Only in COSRX (8)
pentylene glycolzinc pcatrehalosexanthan gumpullulanallantoincitric acidtocopherol
Only in Peach & Lily (13)
propanediolprunus persica (peach) fruit extractdioscorea japonica root extractadenosinemadecassosidehydrolyzed hyaluronic acidhydrolyzed corn starchbeta-glucansaccharide isomeratephytic acidsucroseasiaticosidecaprylyl glycol

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.

Peach & Lily
Hydration standout

Users consistently report improved hydration and a plumper, more luminous appearance. Many describe the 'glass skin' effect as real.

Sensitive skin safe

Eczema-prone and reactive skin users frequently report no irritation. Popular first serum for those new to actives.

Texture praise

Lightweight gel texture absorbs quickly. Some note a slight initial tack that disappears once fully absorbed. Layers well.

Fading scars

Multiple users report gradual fading of acne scars and improved evenness over weeks of use.

Repeat purchase loyalty

High repurchase rate in reviews. Users describe it as a staple they consistently return to.

View Full Product Details

Related Comparisons