How does laser hair removal work?

Laser hair removal addresses unwanted hair. Of course many of us prefer to keep some hair on our bodies, like on our heads. But other areas where hair grows on our bodies can be preferred by some and unpreferred by others. Thankfully today, there are ways to get rid of unwanted body hair, even permanently. Namely, this is with electrolysis or, a more modern way, with laser hair removal. But how does laser hair removal work?

In this article we’ll explain the science behind lasers that remove hair follicles and what you can expect from this treatment.

The lasers that remove hair

Laser hair removal works by way of lasers of course. But only specific wavelengths of lasers. Laser hair removal is considered a medical aesthetic procedure, because lasers can be dangerous to work with. One needs a license to operate lasers, and usually they are only found in doctor’s offices, where a doctor oversees treatments that a laser technician performs.

Lasers emit energy in light form. This energy is heat based. Since colour absorbs light, pigment in the hair follicles absorb the heat from the laser. This then kills the hair follicle so that it can no longer regrow hair.

Who is a good candidate for laser hair removal?

Laser hair removal works best on those with light skin and dark hair. The more the line between the colour of hair and the colour of skin gets ‘blurred’ (so to speak), the less effective laser hair removal can be.

For example, dark skin contains pigment which can absorb laser light. This is not the area that is designed to be treated with the laser, and so it can burn the skin, which is an undesirable side effect. Even if the hair itself is dark, it does not mean the laser can avoid pigments in dark skin.

Since laser hair removal depends on pigments absorbing light, it also will not work on light skin with light hair. In fact, it can be nearly impossible for peach fuzz, or blond or orange haired people to undergo laser hair removal.

How many treatments does laser hair removal require?

Each person’s hair follicles will be different, as will their density and amount of hair. For this reason it is hard to predict how many treatments every person will need to get rid of unwanted hair. It is not a one-size-fits-all treatment. 

Usually, 20% of hair can be removed in a single treatment. This is provided that a good laser designed for the right skin type is used, along with the right settings for the individual patient.

For most people it can take about 6 to 8 sessions to remove most hair permanently. It is not possible to remove more than 90% of hair with laser hair removal.

Laser hair removal can, overall, cause hair to grow back thinner as well. This can make maintenance easier. Remaining hairs can be removed by electrolysis.

What areas can be treated with laser hair removal?

Laser hair removal works on men and women in almost all areas of the body. For example:

  • Back hair
  • Leg hair
  • Arm hair
  • Hand hair
  • Chest hair
  • Buttocks hair
  • Pubic hair
  • Face and neck hair

It is tricky to do laser hair removal on part of the eyebrows, because they need to maintain their shape. The laser beam may accidentally zap hairs that one wants to keep. But if one wanted to get rid of all eyebrow hair, this would be possible with laser hair removal. 

Remaining hairs would need to be removed by electrolysis after the laser has done all it can to remove 90% of hair follicles.

If you have a double chin and are using your beard to hide it, fear not: you can get rid of a double chin with multiple, non-surgical medical aesthetic treatments which are often found in the same clinic as laser hair removal. Then, instead of shaving, laser hair removal can be a great alternative, so you can sport a clean-shaven look.

What can one expect in their first laser hair removal appointment?

Before coming to your first laser hair removal appointment, you will be asked to shave the treatment area. If it is not shaved, it may be shaved at the clinic. The reason for shaving is so that the laser:

a) doesn’t burn your skin as it delivers energy to hairs that lay against your skin.

b) reaches further down into the hair follicle so it can be destroyed at its root.

You’ll be asked to remove clothing so that the treatment area is free of obstruction to the practitioner.

Depending on the type of laser being used, a cold gel or ice pad will be applied to the treatment area before the laser beam is targeted onto it. This is because skin needs to remain cool as the laser heats up the hair follicle, to avoid burns. Some modern laser hair removal devices do not require icing in advance. They come with built-in cooling mechanisms to keep the skin cool during the treatment. These lasers go much faster than traditional lasers for removing hair.

If using the ice or gel method, you may get a little wet. It helps to bring an extra pair of clothing just in case. Or your practitioner will provide you with temporary clothing to wear during the treatment.

When the laser beam energy is activated, the laser technician will begin pulsing the laser on the skin bit by bit. This may have a slight stinging sensation to it. Some people describe it as an elastic band being snapped against the skin.

This treatment is usually tolerable for most people, as long as the cooling mechanisms are in place during the treatment. However, if the feeling is very, very uncomfortable, you should let your technician know so that they can adjust the settings if need be. This is especially important if you have dark skin.

After your unwanted hair is fully treated by the laser, you will be required to come in for another appointment in about 6 to 8 weeks. The process repeats itself until your hair is showing final signs of reduction.

What are the side effects of laser hair removal?

Immediately after the treatment you may have some redness and swelling, but this is normal and should subside within a few hours. You can apply aloe vera to soothe the area if necessary.

Laser hair removal is a treatment that does not require downtime. You can go to work or your normal activities right away. However, most people may not feel comfortable exercising until the redness calms down. Tight clothing may also be uncomfortable immediately after treatment.

More serious side effects of laser hair removal have a lot to do with the practitioner’s safety measures. If they are doing their job correctly, you should not experience severe side effects. However, it’s common to get inflamed hair follicles, which can look like acne. You may also experience razor burn from the shaving. In extreme cases, post-inflammatory hyperpigmentation, also known as skin darkening, can occur. It’s important to work with your provider to address these situations. They may require follow up treatments to reduce the darkening.

To avoid post-inflammatory hyperpigmentation it will be pertinent that you avoid sun exposure before and after your treatments. You should not be tanned at all when getting laser hair removal.


Laser hair removal is a worthwhile procedure for the right candidates who want to remove hair on parts of their body that the laser can treat. Those with dark skin, or tanned skin, should avoid high temperatures from the laser hitting their skin because of how laser hair removal works. However, an experienced practitioner should still be able to treat darker skin types with laser hair removal.