How Do Laser Hair Removal Machines Work?

by Véronique Raymond
Published: Last Updated on
laser epilation and cosmetology

Laser hair removal machines use light energy to zap hair follicles and damage the root when they are in the active growing phase to remove the body hair and to keep new hairs from growing.

The laser hair removal machine starts by dispersing a laser beam of light energy into the pigment of the hair called melanin. The light energy heats the pigment in the hair follicle to cause significant damage to the hair follicles. This causes the current hair to fall out and prevents new hairs from growing. 

Laser hair removal machines are designed to identify the color contrast between the hair color and skin color. This allows the light energy from the beam of light to centralize in the pigment and damage the hair follicle. 

Darker skin tones and light hair aren’t as receptive to laser hair removal machines simply because it is difficult for the light energy to find the pigmentation in the hair follicle. Without the light energy becoming absorbed in the melanin, the hair follicle won’t become damaged. 

Laser hair removal machines don’t cause permanent hair reduction, but they significantly reduce it. In order for laser hair removal machines to work, it has to damage the hair follicle. The damage causes the hair to fall out and prevents it from regrowing quickly. You will need to continue using a laser hair removal machine to ensure the hair follicles remain damaged to prevent future regrowth. 


How Do At-Home Laser Hair Removal Machines Work?

If you’re buying a home laser hair removal device, you’ll need to understand how they work and what type of laser is used in the device.

Home laser hair removal devices use IPL or intense pulsed light technology to treat areas of the body remove hair and slow future hair growth. IPL hair removal is safe and effective for at-home use.

Intense pulsed light uses a broad spectrum of light that has multiple wavelengths. Multiple wavelengths are gentler on the skin and hair than harsher laser treatments. Because of this, IPL devices require frequent touch-ups to achieve hair-free results; however, the treated areas will have smooth skin after just one treatment. You will just have to perform additional follow-up treatments to achieve near-permanent hair removal.


IPL Treatment Areas

IPL works best on light skin and dark hair. The intense pulsed light needs to be able to identify the hair separately from the skin. Essentially, it needs to know where the hair begins and where the skin ends. That’s why dark skin and dark hair aren’t as affected by IPL technology as light skin and dark hair are.

Additionally, if you have red, gray, or light blonde hair, IPL technology won’t work because of the pigmentation in the hair. The pigmentation that makes hair gray, light blonde, or red doesn’t absorb the light energy from the laser. Without absorbing the light energy from the laser, the hair follicle doesn’t become damaged to make the hair fall out and stop growing.

You should use an IPL hair removal machine on small areas of the body including the underarms, bikini line, and legs. Because IPL hair removal machines use wavelengths of laser energy, they are often more gentle on the skin and allow those with all skin types including sensitive skin to use them.

Many of the machines are built with skin sensors that will determine the level of intensity that the laser should use. This makes at-home laser hair removal machines a safe and effective method of laser hair removal.


Side Effects

Laser hair removal machines are safe to use but there are some minor side effects that can occur after undergoing a laser hair removal treatment.

Redness, Irritation, and Swelling

The most common side effects of any hair removal method are redness, irritation, and swelling. Even with plucking, waxing, and shaving, your skin can become irritated. This is common with laser hair removal treatments as well.

Redness, irritation, and swelling will generally improve within just a few hours after treatment. If you notice your skin is still irritated and swollen, you can use a topical cream to help relieve the discomfort.

Pigment Changes

Another common side effect of using a hair removal machine is pigment changes in the skin. Skin can become lighter or darker after using a laser hair removal machine. These pigment changes are only temporary and the skin color should return to normal after just a few days.

Your skin can lighten after laser hair removal treatment if you have darker skin tones or you haven’t avoided sun exposure after treatment.

Eye Injury

Laser hair removal devices use light energy and laser beams of light to zap various areas of the body. When laser hair removal machines are used on the face like the upper lip and chin, you run the risk of injuring your eyes. You will need to wear protective eye gear to ensure your eyes stay protected during laser hair removal treatment.


The most serious side effect that can occur during laser hair removal treatment is blistering. Blistering is very rare but it can happen. If you have suffered from blisters during laser hair removal treatment, you should see a dermatologist to get the appropriate skincare treatment.

The dermatologist will likely prescribe a topical cream that will help heal the blisters and alleviate the pain.


What to Do Before and After Laser Hair Removal Treatment

It’s important to prepare the skin before laser hair removal treatment so that the laser hair removal machine works effectively.

Before using a laser hair removal machine, you should avoid sun exposure. Sun exposure affects the pigmentation in the hair and skin. Because laser hair removal devices work by targeting the hair pigments, sun exposure can change how well the laser hair removal machine works in removing hair.

You also shouldn’t be actively using self-tanner or lying in a tanning bed. Artificial sun exposure, even in the form of a cream, can affect the pigmentation in the skin and cause the laser hair removal machine to work ineffectively.

If you have recently plucked or waxed your hair, you should wait at least 4 weeks before using a laser hair removal machine. The hair follicle will be disturbed during plucking and waxing, causing the hair follicle to not respond as well as it should when a laser hair removal machine is used.

What you can do is shave the area that you want to treat with a laser hair removal machine. Shaving helps prevent any surface hairs from burning. The laser hair removal machine can still detect the hair follicle root in the skin even if the surface hair has been removed.

After you have undergone laser hair removal treatment, you may notice that your skin is red and irritated. You can treat this with ice or a topical cream to help alleviate any discomfort.

You should also avoid prolonged sun exposure, including natural sunlight and tanning beds, for at least six weeks after laser hair removal treatment.



Laser hair removal machines work by damaging the hair follicle to cause the hair to fall out and reduce how fast the hair grows back. The light energy from the laser hair removal machine locates the melanin in the hair follicle to heat it, damage it, and cause it to fall out.

This process will need to be repeated to ensure the hair doesn’t grow back. Laser hair removal machines don’t cause permanent hair reduction, but it does significantly slow the time it takes for the body hair to regrow.


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