Extended Theory of Selective Photothermolysis: A New Recipe for Hair Removal?
December 2001
in “
Lasers in Surgery and Medicine
”
selective photothermolysis laser hair removal LHR hair follicles bulge area stem cells hair regeneration permanent hair reduction power densities skin cooling temporary growth delay permanent hair removal darker skin in-vitro results follicle destruction laser hair removal LHR hair follicles stem cells hair regeneration permanent hair reduction skin cooling temporary growth delay permanent hair removal darker skin in-vitro results follicle destruction
TLDR Permanent hair removal is hard, but using longer laser pulses at lower power might improve results.
In the 2001 paper by E. Vic Ross, the extended theory of selective photothermolysis was discussed, suggesting that the pulse-widths used in laser hair removal (LHR) might be too short and should be closer to half a second for better efficacy and skin cooling. The paper reviewed the biology of hair follicles, emphasizing the targeting of the bulge area where stem cells responsible for hair regeneration are located. It was noted that permanent hair reduction is difficult due to the resilience of these stem cells, and that lower power densities could still achieve stem cell death. The study concluded that while temporary growth delay is achievable, permanent hair removal is challenging. The theory supports the use of low power density for hair removal, particularly in darker skin, but further research is needed to confirm if the in-vitro results translate to consistent hair reduction and to establish reliable parameters for permanent follicle destruction.
