TLDR Hair loss is mainly caused by a testosterone byproduct, and hair restoration surgery uses hair from the back and sides of the scalp.
The document from 16 years ago discussed the cause of permanent hair loss, largely attributed to the testosterone metabolite, dihydrotestosterone (DHT). DHT was found to "turn off" genetically sensitive follicles, typically located in the frontal or frontoparietal scalp, leading to what is known as male pattern baldness. The follicles in the occipital and parietal regions of the scalp were identified as the donor areas for restoration surgery. It was noted that a balding person typically had between 5000 and 6000 follicles available for hair donation, having lost up to 30,000 follicles.
8 citations,
September 2010 in “Journal of Men's Health” Androgenic Alopecia, a common hair loss condition, can be effectively treated with finasteride and other treatments.
8 citations,
October 1988 in “Clinics in Dermatology” Current research explores hair growth drugs, while future research aims for personalized treatments.
May 2023 in “Experimental Dermatology” Male pattern hair loss may be linked to the developmental origins of hair follicles.
12 citations,
July 1993 in “The journal of investigative dermatology/Journal of investigative dermatology” Certain sex hormones and antiandrogens can either slow down or speed up the growth of human hair follicle cells depending on their concentration.
34 citations,
February 1992 in “The Journal of Clinical Endocrinology and Metabolism” Finasteride and minoxidil together promote hair growth better than either alone.
19 citations,
June 2002 in “American Journal of Dermatopathology” Apoptosis contributes to hair loss in androgenetic alopecia.
