Most hairs emerge from the scalp in groups of two or three. About 15 percent of hairs emerge as single hairs and another 15 percent in groups of four or five hairs. These small groupings of hairs are called Follicular Groups or Follicular Units (FUs). FUs are the building blocks of most modern hair transplanting. They are typically obtained by sectioning with the aid of a 6x-10x magnifying “stereomicroscope,” an 8mm- to 10mm-wide strip of skin that is excised from the donor area.
The advantage of transplanting exclusively with Follicular Unit Transplanting (FUT) is that a single session in a bald area or an area that is destined to become bald will result in a perfectly natural appearance. The donor site is sutured closed leaving only a narrow scar when the wound is completely healed in seven to 10 days. The donor scar also is usually excised within any subsequent transplant donor strip(s), so only a single scar is present in the donor area no matter how many transplants are carried out.