bornfreeeee
Dry/Sensitive
I use this serum that contains both C and niacinamide, but admittedly I don't know the percentages. It also contains retinol and I've never experienced irritation from it.

SKIN&LAB
Vitamin C Brightening Serum
4.5
(780)
1233
1
0
Grethi
Oily/Sensitive
I have tried vitamin C serum (30% pure vit C) and niacinamide serum fromInkey list (10% niacinamide) and it worked fine for me
1
0
MindForSkincare
Oily/Sensitive
I think it depends on your skin and on the formulation of the products you are using. Both ingredients can be used in one product that is stable and works. You can layer products and it will be ok or it won't.
There is no one answer, I say give it a go but be ready for a reaction (and report back here).
I once layered niacinamide and vit c (both from TO) and experienced irritation.
0
0

