7 days. The silk purifier uses patented painless high-frequency technology, which can thermally coagulate the hemoglobin and endothelial cells in the expanded capillaries within milliseconds, thereby instantly sealing the expanded blood vessels. This technology is extremely High energy density, instant coagulation, any coagulated skin tissue will fall off in 7 days. The silk purifier is a beauty instrument that can eradicate red blood filaments with high frequency and painlessness in one go.