Compare Products: The Niacinamide 15 Serum vs Deep Vita C Capsule Cream

COSRX

The Niacinamide 15 Serum

Mid-range15%
$25 / 20ml — $1.25/ml
Medicube

Deep Vita C Capsule Cream

Mid-range
$29 / 55ml — $0.53/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
Medicube
  • Those seeking a vitamin C cream with interactive capsule texture
  • Users who want multiple brightening actives in one product
  • People looking for sea buckthorn-based hydration
  • Those who enjoy K-beauty innovation in texture
  • Users targeting dark spots and uneven tone

Key Ingredients

COSRX

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

Medicube

50% Sea Buckthorn Water, 5% Niacinamide, Pure Vitamin C (Sodium Ascorbyl Phosphate), Ferulic Acid, 5 Vitamin C Derivatives

Product Composition

18% similarity (9 ingredients in common)

Shared Ingredients
waterpentylene glycolniacinamidebutylene glycol12-hexanediolethylhexylglycerinsodium phytatetocopherol
Only in COSRX (7)
acetyl glucosaminezinc pcatrehalosexanthan gumpullulanallantoincitric acid
Only in Medicube (35)
methylpropanediolpropanedioldipropylene glycolcaprylic/capric triglycerideglycereth-26cetearyl alcoholargininecetearyl olivatesorbitan olivateammonium acryloyldimethyltaurate/vp copolymerhelianthus annuus (sunflower) seed oilglycine soja (soybean) oilbixa orellana seed oilsimethiconecarbomerhydrogenated lecithinpanthenolfolic acidpyridoxinebiotincyanocobalaminthiamine hclbeta-caroteneriboflavinlinoleic acidpolyisobutenepolysorbate 20sorbitan isostearateadenosinefragranceglyceryl stearatehydrolyzed sclerotium gumgluconolactoneascorbyl propyl hyaluronatealpha-arbutin

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.

Medicube
Brightening glow effect

Users report an immediate brightening and glowing effect after application. The sea buckthorn base contributes to a warm, luminous finish.

Fun capsule experience

Like the collagen capsule cream, users enjoy the interactive texture of bursting the vitamin capsules.

Gradual dark spot improvement

Long-term users note gradual fading of dark spots over 4 to 8 weeks of consistent use.

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