All hairs have different cycles of growth and are not visible on the surface of the skin at the same time. Hair normally grows at its usual cycle and then naturally sheds and replaces itself. Following active growing periods, most hair follicles go into a dormant stage. The period of dormancy may last for an indefinite period of time, however, replacement hairs usually appear within 3 to 12 months. The appearance of these coarse replacement hairs from dormant hair follicles should not be mistaken as regrowth from previously treated follicles.