The concentration and purity of nicotinamide skin care products are the two main factors.
The concentration of nicotinamide will affect its effectiveness. There is no clear evidence of a moisturizing, whitening, or anti-aging effect of nicotinamide at levels below 2%. At concentrations above 10%, the irritation may be too high. It has been found that 2-5% nicotinamide concentration is the ideal range of application in the skin care industry.
Nicotinamide has a twin called niacin, and both are members of the vitamin B3 family and can be converted into each other under the right conditions. If there are too many niacin impurities in nicotinamide cosmetics, it will not only reduce the whitening effect but also the skin surface capillary dilatation, which will increase skin flushing, itching, and other adverse reactions, therefore, when choosing nicotinamide skin care products, we must pay attention to choose nicotinamide skin care products with good purity and high stability.