Niacinamide is an active form of Vitamin B3 found in animals and plants. Niacinamide gives optimum results at pH of 5-6.
It's fine to layer niacinamide with other serums in your skincare regimen because your skin absorbs the niacinamide serum instantly. However we do not recommend mixing niacinamide into a direct acid solution.
Niacinamide can hydrolyze and form nicotinic acid at higher or lower PH, which can result in skin irritation.