# Laser Hair Math - Addition and Subtraction

**URL:** <https://boards.straightdope.com/t/laser-hair-math-addition-and-subtraction/301263>\
**Category:** Factual Questions\
**Created:** [April 26, 2005, 10:40pm UTC](https://boards.straightdope.com/t/laser-hair-math-addition-and-subtraction/301263 "2005-04-26T22:40:03Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![ShibbOleth](https://avatars.discourse-cdn.com/v4/letter/s/848f3c/32.png) [@ShibbOleth](https://boards.straightdope.com/u/ShibbOleth)\
**Post date:** [April 26, 2005, 10:40pm UTC](https://boards.straightdope.com/t/laser-hair-math-addition-and-subtraction/301263/1 "2005-04-26T22:40:03Z")

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Recently I’ve heard a radio ad for some local hair clinic claiming that they can use some laser (_nearly_ painless) to replace hair. I’m guessing this is some new version of transplantation surgery. I also hear and see a lot of spots for laser hair removal.

So, do lasers remove hair or add hair? How do they do both? 😕

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**Author:** ![audiobottle](https://avatars.discourse-cdn.com/v4/letter/a/bc8723/32.png) [@audiobottle](https://boards.straightdope.com/u/audiobottle)\
**Post date:** [April 27, 2005, 12:05am UTC](https://boards.straightdope.com/t/laser-hair-math-addition-and-subtraction/301263/2 "2005-04-27T00:05:11Z")

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I don’t know about hair transplantation, but I would guess the hair removal is done by killing the follicle. It absorbs enough energy from the laser that it dies.

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**Author:** ![Una\_Persson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/una_persson/32/346_2.png) [@Una\_Persson](https://boards.straightdope.com/u/Una_Persson)\
**Post date:** [April 27, 2005, 2:20am UTC](https://boards.straightdope.com/t/laser-hair-math-addition-and-subtraction/301263/3 "2005-04-27T02:20:17Z")

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Laser definitely will remove hair, with greatly varying levels of effectiveness depending on a wide array of factors. Both Fierra and I have had lots of laser done (armpits, legs…other things), and have had great success.

I have never heard of lasering to increase hair growth. Statistically speaking, in some hair removal studies there are sometimes a very tiny number (\< 2%) who see increased hair growth, but I think this is either a fluke or observer error, IMHO.

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**Author:** ![ShibbOleth](https://avatars.discourse-cdn.com/v4/letter/s/848f3c/32.png) [@ShibbOleth](https://boards.straightdope.com/u/ShibbOleth)\
**Post date:** [April 27, 2005, 11:38am UTC](https://boards.straightdope.com/t/laser-hair-math-addition-and-subtraction/301263/4 "2005-04-27T11:38:40Z")

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Okay, burning out follicles makes some sense, I suppose. But still no ideas on how lasers are used to make hair grow (or transplant new hairs)?

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**Author:** ![Philster](https://avatars.discourse-cdn.com/v4/letter/p/13edae/32.png) [@Philster](https://boards.straightdope.com/u/Philster)\
**Post date:** [April 27, 2005, 4:14pm UTC](https://boards.straightdope.com/t/laser-hair-math-addition-and-subtraction/301263/5 "2005-04-27T16:14:15Z")

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There are these laser combs that claim to be able to stimulate hair follicles into regenerating. Removing hair = higher doses

Search on laser hair comb, or read/look here:

> **[Laser Comb Product Review - Does it really work?](https://www.hairlosstalk.com/treatments/laser-comb/)**
>
> The HairMax Laser Comb - see the studies, the pictures, and an honest review of whether this product actually works to treat hair loss.