Chapter 4 - Laser Hair Removal – How Does It Work?

From TheGuide

In today’s glamour-oriented world, where women can feel that they are expected to look like they stepped off a Vogue cover page, unwanted hair is a big issue. Life’s getting busier too, and there’s only so much leisure time. Spending hours removing all your hair off our arms, legs, back, bikini, and other areas seems ridiculous.

People who try laser hair removal are intimately familiar with issues relating to shaving and waxing because often, they have suffered with them in the past. The reason you might gravitate toward laser hair removal is that you are unsatisfied with the temporary nature of shaving and waxing. More and more people are seeking a permanent solution.

How do lasers permanently remove hair?

Laser hair removal works by sending a targeted pulse laser light directly into your hair follicle. The light is absorbed by the melanin (or pigment) in your hair follicle and converted into heat, which permanently disables your hair follicles from growing a new hair.

Laser hair removal requires between five and seven sessions for best results – a permanent reduction of approximately 95-99% of your unwanted hair.

The three phases of hair growth

Let’s go a little further to explain why multiple laser sessions are required. The effectiveness a laser hair removal session depends on your body’s natural hair growth cycle. Your hair grows in a cycle of three phases. The cycle cannot be ignored or accelerated; genetics determine the length of time that each phase lasts.

Stage 1: Anagen

The anagen phase is the active phase of hair growth. During this phase, the follicle bulb is full of concentrated melanin. During this phase hair growth can be as much as 1cm every 28 days.

Stage 2: Catagen

The catagen phase is the regressing phase of hair growth, and can last up last 2 to 3 weeks. The lower part of your hair stops growing but your hair is not yet ready to fall, and the follicle is re-absorbed into the lower layers of your skin.

Stage 3: Telogen

The last phase of hair growth is called the telogen phase. It’s a resting period, during which old hair falls, opening the way to new hair production.

At any given time, the hundreds of thousands of hairs growing on your body can be in any of the three stages of the growth cycle. A laser hair removal session is most effective in the anagen phase of your hair growth cycle (during which your hair has the most melanin or pigment).

The function of the laser is to destroy your hair follicle. The energy from the laser light beam is absorbed by the melanin, the pigment that gives color to hair and becomes the target of the laser. Successful laser hair removal must include multiple sessions scheduled at varying intervals to ensure that each hair can be treated in its anagen phase.

Special Considerations for Darker Skin

For laser hair removal, the most commonly used lasers are the Alexandrite laser and the Nd:YAG laser. The Alexandrite laser emits light at wavelength of 755nm. The Nd:YAG laser emits light at a longer wavelength of 1064nm. Some centers use IPL – intense pulsed light – systems, but these systems are not lasers, and are generally thought of as antiquated an inferior to true laser systems.

As we discussed earlier, in laser hair removal sessions, the laser targets the melanin pigment in the hair shaft. To get to the hair shaft, the laser light must first go through the layer of skin containing melanin. If there is melanin in your skin, the melanin will absorb the light energy from the laser, as opposed to allowing it to be absorbed totally by the base of your hair follicle. The melanin will also convert some of the laser light energy into heat, which may injure your skin.

Longer wavelength laser light allows an experienced practitioner to perform laser hair removal on most darker-skin clients. Melanin is designed to absorb short wavelengths of light such as UV light. The ability of melanin to absorb light decreases as the wavelength of the light gets longer.

To treat clients with dark or tan skin, it’s therefore necessary to use the 1064nm Nd:YAG, rather than an Alexandrite laser or IPL system. The Nd:YAG has a longer wavelength, and therefore, the melanin in a darker-skin client will absorb less of the energy of the laser, which allows the laser to appropriately target the hair follicle.