Niacinamide: The Misunderstood Multi-Tasker in Your Routine

What Niacinamide Actually Does

Niacinamide works through multiple, distinct mechanisms simultaneously — which is unusual for a single molecule:

• Melanin transfer inhibition: Niacinamide inhibits the transfer of melanosomes (melanin-containing vesicles) from melanocytes to keratinocytes. It does not inhibit melanin synthesis itself — which means it cannot cause hypopigmentation or bleach healthy tissue. This is the mechanism behind its brightening effect.
• Barrier reinforcement: Niacinamide stimulates the production of ceramides and free fatty acids in the stratum corneum, directly strengthening the lipid matrix of the skin barrier. This is a genuine structural effect — not simply surface moisturisation.
• Sebum regulation: At concentrations of 2–4%, niacinamide has been shown to reduce sebum excretion rates by approximately 10–15%, which contributes to pore appearance improvement and reduced congestion over time.

The Vitamin C Myth

The concern that niacinamide and Vitamin C should not be mixed derives from early research suggesting the combination could form a yellow compound called nicotinic acid (niacin) that causes skin flushing. More recent studies demonstrate that this reaction only occurs at elevated temperatures (above 70°C) and extended timeframes — conditions that do not exist on human skin. Under normal skin conditions and at typical cosmetic concentrations, niacinamide and Vitamin C can be layered or used in the same routine without issue.

The Right Concentration

The evidence base for different effects varies by concentration: pore minimisation and sebum reduction are documented at 2–5%, while meaningful pigmentation correction requires 10%. Our Rhodo Cica 5D Bright Serum uses 10% niacinamide, which is why it delivers results beyond what a typical B3-containing moisturizer can achieve.