All hairs have differing cycles of growth activity and are not visible on the surface of the skin at the same time.
The (3) stages of hair growth are:
- ANAGEN - active growing phase in which the bulb is in tact
- CATAGEN - is when the lower part of the hair stops growing
- TELOGEN - is the resting phase
Hair normally grows for its usual cycle and then naturally sheds and replaces itself. This 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.