When you understand how lasers work to kill hair follicles, it's clear why it doesn't work on red, blond, gray, or colorless hair. The laser energy has to be absorbed by the hair and conducted down to the root so that the hair papilla is heated to around 130 deg in order to destroy it and neighboring germ cells.
Light colored hair will not absorb enough energy to achieve that temperature. Thermolysis uses high frequency EM (microwaves) to excite the moisture in the dermis at the tip of the probe to achieve the required temperature regardless of the color of the hair or skin.
As you age, your skin gets drier so that thermolysis and blend electrolysis become less effective. For thermolysis, the tip of the probe must be inserted near the papilla for the follicle to be killed. It's not a precise process, and not everyone has hair which is easy to kill, so multiple treatments are usually needed to finally kill a follicle.
Many clients are very sensitive to pain especially near the nose, mouth and ears. An electrologist will reduce the energy level to where the client can tolerate treatment. Unfortunately, lowering the energy level also reduces the chance of killing the follicle.
Blend works by electrolysis supplemented by RF to create hot lye. The lye travels down the hair shaft to the papilla and destroys the cells very close to it. Thus, blend is much less likely to cause permanent damage (scarring) on your face. Unfortunately, it takes about 12 seconds to treat a hair by blend so the cost to treat a full beard is too expensive for 95% of clients.
Almost any electrologist can use blend safely and effectively. Precise location of the probe is not as critical as with thermolysis, since the means to killing the follicle is not temperature, but alkaline burning.
Laser, followed by judicious use of thermolysis, and finally blend will help to avoid visible skin damage which leaves an orange peel texture to the skin where facial hair is most dense.
