What is laser hair removal and how does it work?
As laser hair removal becomes an increasingly popular procedure for all those "in-the-know," it's important to understand what, exactly, laser hair removal is. Basically, laser light and heat is absorbed by the pigment in the hair follicles - causing the follicle to enter the telogen phase of hair growth. The "permanent" aspect of laser hair removal comes from multiple consistent treatments; forcing the follicle to stay in the telogen phase each time it begins to "wake up" causes the follicle to stay in telogen phase for longer and longer periods of time. This is why any place that tells you laser hair removal is permanent just doesn't understand the science. Laser hair removal messes up your body's natural urges to produce hair - and nature doesn't give up easily.
Check out the graph above: our aim is to target the hair after the catagen phase of hair growth, and target it consistently to weaken the hair follicle and force it into the telogen phase for longer periods of time. Many factors can cause the hair follicle to leave the telogen phase - hormones is one of them. Puberty, pregnancy, and other hormonal-related occurrences can reawaken resting hair follicles, and cause hair to grow, even if you've had a ton of laser treatments before.
Laser hair removal is most effective on light-skinned people with darker hair - the laser light and heat is absorbed into the melanin of hair follicles more quickly and efficiently. It's important to maintain a delicate balance with laser hair removal, because the laser light has to stay on the hair follicle long enough to damage it, but not so long that the skin around the follicle is damaged as well. That's why you'll often hear stories of burns or ineffectiveness - it takes a few sessions to even find that delicate balance, and your hair follicles often adapt to the laser that is damaging it. Gradually, the intensity of the laser treatments has to be stronger to combat the most stubborn of hair follicles.
First, it's important to be realistic about your expectations and your candidacy. If you have very blonde or white hair, laser hair removal might not be the hair removal option for you. Even after 6 or 10 or 15 sessions, the hair in that area might still persist, because there is no melanin/pigment in that area to absorb the light and heat of the laser. Second, the finer your hair is, the less likely it will be for laser to find and target it. Third, it's important to be consistent with your laser treatments - follicles will respond the most to damage if it is done on a steady basis. When starting laser hair removal for the first time, make sure you space out your sessions four weeks apart. Eventually, your technician will advise you to wait longer periods of time, and your hair follicles will be dormant for longer. Fourth - give laser hair removal the best chance possible! Don't wax, pluck, or tweeze two weeks before your treatment; this keeps the follicle intact so that the lasers can do their most effective work. Being in the sun is a big no-no as well, since areas treated by laser are prone to micro- and macro-pigmentation (dark or white spots).
Everyone is different, so be wary of places that guarantee permanent removal in a definitive amount of sessions, or places that only provide one type of laser.
Good luck - and enjoy!