In recent years, people have bred freshwater pearls as a substitute for natural pearls that occur in seawater, and they have also developed water-soluble pearl powder (P-w) and ultra-micro (P-μ) and ultra-nano pearl powder (P-n) products. However, neither the scientific value of pearl powder, nor the differences in efficiencies of different pearl powder products is still unknown. In this study, the effectiveness of three kinds of pearl powder products in various applications was compared. Tests for transepidermal water loss (TEWL) and evaluations of the skin surface hydration of test subjects showed that pearl powder has a satisfactory moisturizing effect on skin and that P-μ has a distinctly stronger moisturizing effect than P-w. The three pearl powder products can also significantly reduce the activation of tyrosinase and free radicals. In tests for reducing power and 1,1-diphenyl-2-picrylhydrazyl (DPPH) for scavenging free radicals, P-n and P-μ showed better performance than P-w. These results provide a reliable scientific basis for the use of pearl powder in beauty treatment, resistance to aging, and clinical medical treatment.
