Fractional Erbium:YAG (or Er:YAG) lasers can lead to scalp hair growth per some recent studies. Both ablative and non-ablative Erbium lasers have been used to treat hair loss.
Note that the fractional lasers discussed in this post have significantly higher wavelengths (1,500-3,000 nm) than typical low-level laser therapy (LLLT) home-use devices (650 nm). Fractional laser treatments must be undertaken at professional clinics and never at home.
Fractional laser treatments are unique in that they work at both the upper epidermal and lower dermal layers of the skin. Other laser light treatments are either ablative or non-ablative.
Here is some information on ablative versus non-ablative lasers and on fractional lasers. Also see this excellent overview from 2012 of all four combinations of lasers being implied here. Note that fractional carbon dioxide (CO2) lasers have also been used for hair growth purposes.
Updated: April 14, 2022
Er:YAG Lasers for Hair Growth
A number of new studies have been published since I originally wrote this post. All seem to use the Erbium lasers for hair growth.
— Ablative fractional 2940-nm erbium:YAG laser to treat hair loss in a male Korean patient. They used the locally made PURAXEL laser. The before and after photo from this September 2021 study is shown below:

— A study from August 2021 concluded that a non-ablative 2940-nm Er:YAG laser is an effective tool in the treatment of androgenetic alopecia. The authors made use of the Fotona’s SP Dynamis laser system in SMOOTH ™ mode.

— A unique 2021 study from Russia found that combination therapy consisting of non-ablative 2940-nm Er:YAG laser plus platelet-rich plasma injections resulted in very significant hair regrowth.
The SP Dynamis (Fontona) fractional laser was utilized in SMOOTH™ mode. The before and after image on the right is impressive.
May 11, 2015
Fractional Laser Hair Growth Stimulation via Wounding
The reason I thought about lasers again this week is because several days ago an interesting May 2015 article from South Korea was published in the Lasers in Surgery and Medicine journal.
The conclusion of this article is that ablative fractional lasers appear to be effective in inducing hair regrowth via activation of the Wnt/Beta-Catenin pathway. I have discussed the Wnt/Beta-Catenin pathway in numerous posts on this blog before. Note that the way these lasers work is somewhat related to the concept of wounding and hair growth.
Apparently, even before this latest development, there have already been a few published journal articles from Asian researchers covering both ablative and non-ablative fractional lasers and their positive impact on hair growth. For example see:
- April 2015: Enhancing hair follicle regeneration by non-ablative fractional erbium-glass laser: The laser wavelength was 1550 nm. Note that the erbium laser is almost always ablative, but this one was non-ablative.
- December 2011: The effect of a 1550 nm fractional erbium-glass laser in female pattern hair loss.
- January 2011: Fractional photothermolysis laser treatment of male pattern hair loss. Also using the 1550 nm erbium-glass laser.
In the latest South Korean study in mice, it was found that the most effective (ablative) laser dosage was “the 10 mJ/spot and 300 spots/cm2 setting”. Hopefully some of these scientists will soon conduct studies on humans to get the most effective dosage on us neglected Homo Sapiens.
It does seem like light amplification by stimulated emission of radiation (LASER) can now legitimately be considered as a tool in the fight against hair loss. It is likely that in the years ahead, scientists will experiment with many newer lasers and with various duration and power settings.