1. Prevent melanin from precipitating into horny cells.
When melanin is transferred to horny cells, it will make skin darker. Niacinamide acts on the already produced melanin, and effectively inhibits the transmission of about 35% to 40% of melanin from melanin cells to keratinocytes. Thus it can reduce excessive melanin deposition. Clinical trials have shown that using niacinamide moisturizer can significantly diminish the area and number of brown spots on the skin.
2. Promote the melanin cells metabolism.
Nicotinamide can be absorbed by cells directly because of its small molecule. It can penetrate into the waterproof layer of skin's corneum within two hours, and act on the inner layer of skin. Applying nicotinamide to the skin can promote the formation of energy molecules in the body. And it passes through the cuticle layer to the dermal connective tissue and fiber. Then it directly reaches the bottom of the cell to promote cell metabolism.
3. Improve skin synthetic epidermal protein
Nicotinamide can synthesize protein on skin's surface. Thus it can improve skin texture and replenish moisture. In 1990, the European patent EP0-396-422 found that adding nicotinamide, sun-screening agents containing UVA, UVB and 0.1% ~ 5% silicone compound into cream formula, that can promote skin whitening and sun protection function.