Why This Question Matters
When brands brief us on a brightening serum, the first question is almost always how to combine niacinamide and vitamin C without instability or irritation.
The Science, Briefly
Early studies suggested an interaction that could cause flushing. Modern formulation practice shows that at appropriate pH and with proper chelation, they can co-exist — with a derivative of vitamin C often being the safer choice.
Our Recommended Approach
Use an ascorbyl derivative at 2-5% together with niacinamide at 2-5%, buffered to pH 5.0-6.0, plus a chelating agent. This delivers both benefits without the color change that consumers dislike.