Which is better: laser or pulsed light?

Laser and pulsed light are different treatments for achieving permanent hair removal. Do you know the differences between them?

Key differences in hair removal

Laser hair removal is based on selective photothermolysis, which involves targeting specific cells or tissues for destruction using light and heat. In this context, the aim is to destroy the structures responsible for hair growth: the hair follicles. The main characteristics of laser light are that it is monochromatic, directional, and coherent, allowing for high intensity without dispersion. It is important to note that there are various types of lasers, and this article focuses on diode lasers due to their versatility.

On the other hand, pulsed light, like any type of light, is characterized by being polychromatic, divergent, and incoherent. The energy is distributed among the different wavelengths that comprise it.

As such, it emits a mixed light, composed of many types of photons, traveling at multiple wavelengths that range from 590NM to 1200Nm.

Both photodepilation methods target the melanin in the hair follicle, and it is reasonable to expect permanent results from both treatments. However, professional photodepilation treatment with laser hair removal offers a better balance between penetration and melanin targeting. Therefore, it is more advisable for depilating darker skin tones and deeper follicles, as it allows concentrating a significant amount of energy in the hair follicle rather than the surrounding skin.

Many pulsed light devices include filters that allow us to alter the wavelength. It is important to acknowledge that these filters will prevent the light from reaching lower wavelength ranges, yet they do not ensure that the light remains at a single wavelength. This means that if we apply an 800 nm filter, the range of light will extend from 800 to 1200 Nm, rendering it less efficient than diode laser.

For medical or aesthetic centers operating with pulsed light, it can entail significant variable costs due to the limited number of shots that lamps can perform, requiring periodic replacement. Although diode lasers have a higher initial cost, they can perform up to 15 million shots without losing potency, needing only an annual maintenance for diode calibration to ensure correct power output.

Pulsed light is noted for being more painful than laser due to the light penetrating the skin in multiple directions, producing a sensation akin to an elastic band snap.

These factors contribute to the declining use of pulsed light for permanent hair removal, whereas diode laser devices are increasingly sought after in aesthetic and medical-aesthetic centers for the purpose of permanent hair removal.