Topical products only dilute the spots on the surface, but cannot penetrate the bottom layer, completely removing the roots of the spots, just like a white wall, the inside is still black, and will rebound even if it is stopped.
The external product is just to dilute the surface spots, but can not penetrate the bottom layer, completely remove the root of the spot, like a white wall, inside is still black, a deactivation will rebound
External products can only dilute the spots on the surface, but they can't penetrate the bottom layer, and completely remove the spot root. It's like a white plastered wall, which is still black, and it will rebound when it's stopped<br>