2nd. Layering would be fine, just wait 10 min between BHA and nia
Oh wow. I'm glad I asked before I purchased the Nia!
Trying to decide between PC Niacinamide booster & Nia Skin Strengthening++
You won't see any visual benefit from once a week, also u can use it with acids(Nia is not an active
2nd all this and for the last question I would consider niacinamide a