The simple answer is 5 – 10%.
Yes, that is correct. Only about 5-10% of hair is affected by the laser on any given treatment. The reasons are quite easy to understand. The primary goal of laser hair removal is not to zap the hair but to zap the blood capillary that is feeding the hair growth. The laser detects that color in the hair and shoots a laser. The hair works like an antenna that transmits all that energy to the blood capillary zapping it and scarring it. Only 5-10% of hair has the blood capillary connected to the root.
If you are a patient of laser hair removal, you know that multiple sessions are required. Each session treats 5 – 10% of hair only. We try our very best to get as close to 80-90%. However, it is important to keep in mind that it is impossible to reach 100%. Our bodies really like to produce new hair every year! The picture above shows an image of all the hair phases and the phase we are looking for is the anagen phase.