Estimating the Number of Lifetime Follicular Units: A Survey and Comments of Experienced Hair Transplant Surgeons

In 2013, a survey of 39 experienced hair transplant surgeons estimated the number of follicular units (FUs) available for transplantation in 30-year-old males with different hair densities and a potential for developing Type V or VI male pattern baldness (MPB). For Type V MPB, average hair density could yield approximately 6,404 FUs, below-average density could yield 4,963 FUs, and above-average density could yield 7,904 FUs. For Type VI MPB, the yields were 5,393 FUs for average density, 4,204 FUs for below-average density, and 6,661 FUs for above-average density. The study concluded that the number of FUs containing permanent hairs is finite and should be considered when planning hair transplants to avoid overly aggressive procedures. Additionally, the document discusses the practice of combining Follicular Unit Extraction (FUE) with strip harvesting and "cherry picking" FUs, acknowledging the risks such as increased sparseness and visible scarring. The conclusion emphasizes the limitations of the Safe Donor Area (SDA) and the importance of conservative approaches in hair restoration surgery to prevent future aesthetic and legal issues.