Tiny pulses of energy pass through the cotton tipped probes into the tissue and muscle and out again to the other cotton tipped probe. The muscle is either stretched or squeezed as the energy passes through. The tiny current stimulates the Golgi mechanism, or brain, of the muscle to remind it what it used to do. As with any muscle work, it takes a number of sessions for the results to build up and stay. As well as affecting the muscle structure, the microcurrent stimulates the collagen production and generally helps with the skin tone.