How does Laser Hair Removal Work?

Woman with smooth, hairless legs following laser hair removal appointment at Mountain Radiance in Asheville

Hey everyone, this is Dr. Mark with Mountain Radiance Medical Spa in Asheville answering some common aesthetics questions. Today’s question is: How does laser hair removal work?

This is a super interesting question and unfortunately involves a little bit of physics, but let’s start with the biology.

The hair follicle grows in several phases, the Anagen, Catagen, and telogen phases. The one we’re most interested in is the Anagen phase where the hair is actively growing and connected to the stem cells that lead to more growth.

How often each follicle is in the Anagen phase varies based on the body area but a good average is about 15-30% of hair in a region will be in the Anagen phase and therefore can be targeted for laser hair removal.

So now for the physics and laser part!

The main physics concept that we’re dealing with for laser hair removal, and actually several other light based therapies as well, is Selective Photo-Thermolysis.  What this means is using specific wavelengths of light to target specific pigments to deliver the right energy over the right time to destroy the cells that lead to hair growth. 

With laser hair removal, what we’re targeting is melanin which is why it works much better on darker hair rather than light hair or small white hairs.   This also explains why people with darker skin tones or tanned skin may not be good candidates for laser hair removal because the melanin in the skin can become a target and lead to hypopigmentation or pale spots.

The laser operator will choose the right energy and time settings to optimize treatment based on a number of patient factors so that we’re getting enough energy to destroy the nearby stem cells and prevent future hair growth, but not too much to burn the surrounding tissue.  

Now, bringing back in the biology part, remember that only about 15-30 percent of the hair follicles are going to be in the right phase where the dark hair is close enough to the stem cells to transfer the energy.  This means that we need to do multiple treatments spaced several weeks apart to allow the hair follicles to transition into the Anagen phase and become targets.

If you were to pluck or wax the hair, or use a depilatory cream like Nair before coming in for a laser hair appointment, what you’re doing is removing the entire hair and it can’t be a target for the laser.  It’s best instead to shave the day before for optimal results. 

Learn more about Asheville Laser Hair Removal at Mountain Radiance

If you’re interested in reducing unwanted hair with a series of Asheville laser hair removal treatments, our our licensed medical technologist Brianna is here to help. Schedule your personal consultation by calling our Asheville med spa at (828) 627-2711 or contacting us online today.

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