Niacinamide and vitamin C are the two most common ingredients recommended for dull skin and uneven tone, and it's easy to assume they do the same job. They don't quite, and knowing the difference makes it easier to pick the right one, or to use both without wasting money on overlap.
What niacinamide does
Niacinamide, also called vitamin B3, is a gentle, multitasking ingredient that helps even out tone, refine the look of pores, calm redness and support the skin barrier, all at fairly low risk of irritation. It suits almost every skin type, including sensitive and acne-prone skin, and layers well with most other ingredients. TIA'M's Vita B3 Source uses a high 10% concentration, while NACIFIC's Phyto Niacin line spreads a gentler 5% across a full routine.
What vitamin C does
Vitamin C is a stronger antioxidant that more directly targets dark spots, pigmentation and dullness, and tends to show visible brightening faster than niacinamide, though often with more potential for tingling, especially at higher concentrations. TIA'M's Vitamin C24 Surprise Serum uses a strong, water-free 22% pure vitamin C, while gentler vitamin C derivatives, found in products like Beauty of Joseon's Glow Deep Serum, are a softer entry point.
Which one should you choose?
- Choose niacinamide if your main concerns are pores, mild dullness or general skin health, or if you have sensitive skin and want a lower-irritation option.
- Choose vitamin C if your main concern is stubborn dark spots or pigmentation and your skin can tolerate a stronger active.
- Use both if you want a fuller brightening routine. They're commonly layered together, with vitamin C in the morning under sunscreen and niacinamide either morning or night.
A note on layering
Older advice warned against combining vitamin C and niacinamide, but current formulations are stable together and layering them is standard practice in most K-beauty routines. If your skin is new to either ingredient, introduce one at a time so you know what's causing any reaction, and always wear sunscreen during the day since both can increase sun sensitivity slightly.
Browse niacinamide and vitamin C products to build your brightening routine.