All informations about laser hair removal

To no longer need to wax, shave nor tweeze to have a smooth skin is a dream shared by many women and which is beginning to inspire more and more men. For some, it is even a necessity, especially in cases of excessive hairiness (hirsutism). Laser hair removal is a key to this liberation.

Here are the most important elements:

  • The laser hair removal principle is to heat the pigment at the base of the hair to burn the hair follicle.
  • After a certain number of sessions (4-6), the hair no longer grows back. Nevertheless, it is necessary to treat again once or twice a year to maintain this effect.
  • There are several precautions, contraindications and possible (minor) side effects
  • It is not suitable for light hairs (white, gray, blond or red).
  • For dark skin, you need a special laser.
  • It is necessary to ensure the competence of the practitioner.

In this site, we present everything you need to know about laser hair removal and we answer your questions . We will present:

  1. How laser hair removal works

2. Precautions, side effects and contraindications

3. Professionals and equipment

1. How laser hair removal works

Melanin has the property of absorbing light, even ultraviolet. This is the function laser hair removal will exploit. The device emits several almost instantaneous flashes which will “grill” the melanin of the hair. Indeed, light is energy and, by being captured by melanin, it is transformed into heat where the melanin is located: in the hair. The base of the hair is particularly rich in melanin.

Thus, the hair heats up, vaporizes its water and burns the entire follicle by “denaturation”. This happens when, from 60°C, the bonds in the protein or collagen molecules tend to break. Of course, the system is not “that simple”. For example, it is necessary to prevent the heat from spreading too far into the skin. For this, the laser uses several flashes spaced a few milliseconds apart. It is also possible to modulate the intensity of the energy transmitted.

We can thus target the follicle avoiding the skin, which will absorb much less light. Obviously it is a process that works better in principle for light skin and dark hair. We will detail this aspect later (dark skin needs special technology). The wavelength is designed to specifically target melanin. If it was too low, the exohemoglobin could absorb it, and if it was too high, water would.

The process is not immediate: it will take several sessions for the effect to be lasting. The first series of sessions generally includes 5 to 8 treatments spaced 4 to 10 weeks apart. Note that it is very variable, depending on the individuals and the areas treated. If it is often described as definitive, laser hair removal actually needs, once the first series of sessions have been carried out, reminders every year.

Be careful not to confuse the laser with IPL (intense pulsed light) hair removal . It’s not the same at all, but many traders maintain the difference.

2. Precautions, side effects and contraindications

To take full advantage of the effect of laser hair removal, you must follow several precautions, know how to identify side effects and know the contraindications.

Precautions to follow

Before waxing

There are several precautions to follow before laser hair removal:

  • You must stop depilating two weeks to a month before each session. The hair must be in a sufficiently advanced phase for the laser to be effective.
  • The hair is shaved before the exhibition. Indeed, otherwise the laser would also heat it, which would not only make it less effective (less energy at the level of the follicle), but also more dangerous, risking burning the outside of the skin.
  • It is necessary to avoid exposure to the sun before, up to 2 weeks, the treatment.
  • Obviously, you must not bleach the hair, otherwise the laser will not work.
  • Tell your practitioner about any medications you are taking to be sure they are not contraindicated.
  • Remove makeup and other lotions from treated areas.
  • Not having undergone botox and other injections within two weeks.

After waxing

After the laser hair removal session, there are several precautions to follow:

  • Avoid high heat, such as saunas or sports
  • Avoid exposure to the sun. Don’t get a tan within two weeks.
  • Avoid photosensitizing products on the treated area in the days following the session
  • Do not have a botox injection and the like within two weeks

To dig further into this topic, you can consult our article about precautions of use for laser hair removal.

Possible side effects

The main undesirable side effect is paradoxical regrowth. The laser will come to stimulate an entire area of ​​the skin and heat a little around. This can cause the surrounding hair follicles to react and start producing hair. This is especially problematic for people with hormonal disorders.

The treatment is a little painful, although not very painful compared to other methods. Devices with dynamic cooling functionality (DCD, Dynamic Cooling Device) further reduce this discomfort. They project a cooling agent before each flash.

There is also a slight risk of depigmentation or hyperpigmentation (especially if we do not respect the precautions related to the sun or the contraindications related to drugs for example).

There is also a risk of burns, especially if the device is set too high.

To dig further into this topic, you can consult our article about side effects of laser hair removal.

Contraindications to laser hair removal

There are several contraindications to laser hair removal:

  • Use of photosensitizing drugs (roaccutane, cortisone, antibiotics, etc.)
  • Skin diseases, such as herpes, psoriasis, vitiligo, etc.
  • Tanning (especially sunburns)
  • The tatoos
  • Pregnancy and breastfeeding, due to hormonal disruption, which makes the procedure less effective

To dig further into this topic, you can consult our article about contraindications to laser hair removal.

3. Professionals and equipment

Professional laser hair removal equipment

Professional laser hair removal requires large-scale, very expensive equipment, which can represent tens of thousands of dollars/euros. The main types of laser are:

  • The alexandrite laser, which wavelength’s is 755nm
  • The diode laser, which wavelength’s is 805 or 810 nm. It is a device that is applied to the skin (much like pulsed light hair removal) and uses an ultrasound gel as a medium. This is a fairly quick solution to operate.
  • For dark skin, the high wavelength (1064nm) “Nd:Yag” laser is used.

There are other technologies, old ones like “Ruby” (694.3nm) or new ones, like LEDs (780-850nm).

There are also accessory devices, in particular to reduce the pain of the procedure. To go further, we will offer you a summary of the different technologies and models.

Laser hair removal professionals

Laser hair removal is a “dangerous” process: a high-intensity laser is used, which can burn the skin. To be safe, this process must be handled by a qualified professional. In some regions, it even has to be a doctor or someone supervised by a doctor. Sometimes it is necessary to have training as an esthetician and/or a special certification. In the United States, this varies by state. For example, in California, you must at least have some nursing training! And again, under the supervision of a doctor.

To choose a “good” professional, we recommend these points of vigilance:

  • Is he selling you the laser as actually being final? Warning: this is false, you need sessions every year to sustainably maintain non-regrowth.
  • Does he offer you both laser and IPL? They are two different technologies. IPL can treat larger areas, but is less effective and less durable.


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