These are the two serums everyone asks about. Both are excellent — but they solve different problems, so the real question isn’t “which is better,” it’s “which does *your* skin need” (and can you use both?).
Quick comparison
| | Niacinamide (Vit B3) | Vitamin C |
|---|---|---|
| Best for | Oil control, pores, redness, gradual brightening | Antioxidant defence, glow, fading dark spots |
| Strength | Gentle, suits most skin | Can be active/tingly; introduce slowly |
| Best time | AM or PM | Usually AM (antioxidant protection by day) |
| Stability | Very stable | Sensitive to light/heat/air — degrades faster |
Read the deep dives: niacinamide guide · vitamin C guide.
Which should you choose?
- Oily/acne-prone, large pores, redness, sensitive → start with niacinamide (gentle, oil-control). Pair with BHA for pores.
- Dullness, dark spots, want antioxidant + glow → choose vitamin C by day, under sunscreen.
Can you use both?
Yes. The old “they cancel out” myth is outdated — modern formulas layer fine. Easiest approach: vitamin C in the AM (with sunscreen) and niacinamide in the PM, or simply layer niacinamide after vitamin C. (See layering order; terms in the glossary.)
Buy authentic serums
Vitamin C especially must be fresh and well-stored to work. At TheSkinProof, every niacinamide and vitamin C serum is invoice-verified, batch-checked and climate-stored, with a 2× money-back guarantee. Browse authentic serums.
Before you buy: check authenticity, not price
Don’t chase the cheapest product — look for the authentic one. A cheap fake can damage your skin, and using nothing at all does less harm than using a counterfeit. But a high price doesn’t guarantee authenticity either — people overpay for fakes too. So judge by authenticity, not price.
TheSkinProof offers free authenticity verification. Message our Facebook page with the product and we’ll analyze it and tell you whether it’s real or fake — so it’s important to verify before you buy anything. Or simply buy from TheSkinProof, where every product is already invoice-verified with a 2× money-back guarantee.