COSRX The Vitamin C 13 Serum vs Isntree C-Niacin Toning Ampoule
Same shelf, different answers — here's the whole picture in one table. Click either product for full ingredient decode, skin-twin reviews and every retailer's landed cost.
| COSRX The Vitamin C 13 Serum | Isntree C-Niacin Toning Ampoule | |
|---|---|---|
| Step | Serum | Serum |
| Price | $21 | $25 |
| Best landed cost | $26.99 | $25 |
| Rating | ★ 4.4 (1,900) | ★ 4.5 (1,900) |
| Evidence grade | A | B |
| Korea signal | — | #20 serum · Olive Young Korea (seed) |
| Hero ingredients | Vitamin C, Hyaluronic acid, Allantoin | Vitamin C, Niacinamide |
| Best for | Dullness, Dark spots (PIH) | Dullness, Dark spots (PIH) |
| Skin types | Normal, Combination, Dry, Oily, Sensitive | Normal, Combination, Oily |
| Texture | light | light |
| Tone note | All tones | All tones |
| Fragrance-free | ✓ | ✓ |
| Fungal-acne safe | ✗ | ✗ |
| US stock | ✓ | ✓ |
Our read: COSRX The Vitamin C 13 Serum carries the stronger evidence grade (A); Isntree C-Niacin Toning Ampoule wins on landed cost. If your concerns match both, evidence is the tiebreaker we'd use.
Prices and rankings are seed data pending weekly verification. Take the 60-second quiz and both products get a personal match score on their pages.