If you are wondering how the Derma-Logi derma roller works, you can think of it as a natural way to help your skin renew itself. The very fine needles are able to target not only the upper layer of the skin known as the epidermis, but also the deeper dermal layer of the skin called the dermis. This skin therapy is minimally invasive and is performed by rolling the derma roller back and forth across the skin in various directions while applying mild pressure.