Compare Products: The Niacinamide 15 Serum vs Vitamin Illuminating Serum

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
EQQUALBERRY
  • Those looking to address uneven skin tone and dark spots
  • Users who want vitamin C benefits without L-ascorbic acid irritation
  • Sensitive skin types seeking a fragrance-free brightening serum
  • People who prefer lightweight, non-sticky serum textures
  • Those interested in barrier support alongside brightening actives
  • K-beauty enthusiasts looking for a multi-functional serum

Key Ingredients

COSRX

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

EQQUALBERRY

40% Acerola Fruit Water, 4% Niacinamide, 2% Arbutin, 5 types of Ceramides, 8 types of Hyaluronic Acid

Product Composition

25% similarity (11 ingredients in common)

Shared Ingredients
waterniacinamidebutylene glycolacetyl glucosamine12-hexanediolxanthan gumallantoinethylhexylglycerinsodium phytatetocopherol
Only in COSRX (5)
pentylene glycolzinc pcatrehalosepullulancitric acid
Only in EQQUALBERRY (28)
arbutinhydrogenated lecithinpentaerythrityl tetrabehenatediethoxyethyl succinatebetaineceramide nphydroxyethyl ureacaprylic/capric triglyceridemelia azadirachta leaf extractcetearyl alcoholsqualanemelia azadirachta flower extractpanthenolcurcuma longa (turmeric) root extractcarbomerbutyrospermum parkii (shea) buttertromethamine3-butanediolocimum sanctum leaf extractcorallina officinalis extractmalpighia glabra (acerola) fruit extractglyceryl stearatehydrolyzed hyaluronic acidhyaluronic acidhydroxypropyltrimonium hyaluronatepotassium hyaluronaterubus fruticosus (blackberry) fruit extractvaccinium angustifolium (blueberry) fruit extract

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.

EQQUALBERRY
Lightweight, non-sticky texture

Users consistently praise the serum for being lightweight and non-sticky. Several reviewers specifically note it absorbs quickly, unlike typical vitamin C serums.

Visible brightening within weeks

Many users report improved skin tone and reduced dark spots within 2 to 4 weeks of consistent use. The brand cites an Intertek study showing 57.49% melanin area reduction in one week, though the full study methodology is not publicly available.

Small bottle size

At 30ml, several users note the bottle runs out quickly, especially with daily use on face, neck, and body as suggested by the brand.

Results vary by skin type

Some users report minimal visible change after several weeks. Most negative reviews cite underwhelming brightening results rather than irritation or breakouts.

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