Observing hair growth in the initial weeks following a hair transplant is a positive sign, however, this does not necessarily mean the procedure has been entirely successful. After the transplant, the grafts integrate with the scalp and begin to receive nutrients and blood supply; the transplanted hair strands may grow slightly during this period, but these are merely the strands remaining above the skin, whereas the crucial elements the hair roots and follicles reside beneath the skin. In particular, the vast majority of the transplanted hair falls out within the first two months a phenomenon known as "shock loss" (shedding). It is important to note that only the hair strands are shed; the hair roots remain beneath the skin and begin to sprout new growth after approximately three months.