How does laser hair removal work?

How does light help to get rid of unwanted hair?

Silky smooth skin has been in fashion since the Middle Ages, so it’s no surprise that countless methods have been developed over the years, with varying levels of success. Despite first launching three decades ago, there is one technique that is still considered at the top of the hair removal game: laser removal.

For the most part, laser hair removal still works as it did back then. Highly concentrated pulses of light at specific wavelengths target and are absorbed by the dark pigment in hair follicles called melanin. The follicles heat up and are destroyed, preventing future regrowth. It’s most effective on darker and coarser hair, with best results achieved via six to ten monthly treatments. This is because each hair goes through a natural growth cycle with a ‘rest’ and ‘fall-out’ phase, meaning not every hair is there to target during each session.

Laser treatments step by step

1. Pre-treatment preparation

Prior to each session customers must avoid Sun exposure for four weeks beforehand as the laser could cause scarring to darker skin pigment.

2. During each session

The laser emits concentrated pulses of light into the hair follicles. Just as the Sun’s rays are absorbed by dark clothing, the dark pigment in the hair follicles absorb the laser’s energy and heat up.

3. After treatment

This heat in the follicle destroys the hair cells, preventing regrowth. Multiple treatments are required as the treatment targets follicles that are actively growing.

This article was originally published in How It Works issue 105, written by Zoe Louise Cronk

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