A larger %age of hair follicles are in resting/ non-growing phase on the body donor areas.
It is advisable to use only the actively growing hair for transplant.
Preshaving the body donor areas is a simple, non-invasive method to locate the actively growing hair.
Please note - The body donor areas should be wet shaved with a razor (trimming with a hair trimmer alone will not suffice), 3 to 5 days before the procedure.
If you have very dense and long hair growth, you may first buzz cut the hair with a trimmer, followed by shaving the hair flush with the skin using a razor.
The duration of the anagen/telogen phase plays an important part overall, while the %age of hair in telogen gains increasing importance with each passing hair cycle.
Talking of durations -
Following is an extract
Hair Growth Tables
There are many factors that affect individual hair growth. These growth tables should only be used as a very generalized guide.
Telogen (%) Anagen (%) Duration of Activity
Scalp 15/ 85/ 2-6 years
Eye Brows 90/ 10/ 4 - 8 weeks
Cheeks 40 - 50/ 50 - 60/
Beard (Chin) 40/ 60/ 1 year
Moustache 45/ 55/ 16 weeks
Arm Pit 70/ 30/ 16 weeks
Pubic Area 70/ 30/ months
Arms 80/ 20/ 13 weeks
Legs & Thighs 80/ 20/ 16 weeks
Carl W. Bushong, Ph.D., LMFT
Richard A. Martin, Jr., M.D., FACEP
Kimberly L. Westwood, CPE, CCE
While the scalp donor hair have a growth phase of, an average, 3 years, most body hair have a growth phase lasting approximately 4 to 5 months.
Therefore, unlike scalp to scalp transplants, BHTs will show a marked cyclic variation.
Also while 85% of the scalp hair are in growth phase at any particular time, 40 to 80% of the body hair may be in telogen (non growth phase).
Thus, the significance of the Preshaving protocol.