Lasers, Wavelength and Hair Growth

I have covered lasers and hair growth on this blog a number of times in the past. A spate of new studies on this subject suggest an emphasis on laser light wavelength during treatment.

New Low Level Laser Therapy Hair Studies

When people discuss laser treatments for hair loss, low-level laser therapy (LLLT) is usually what they mean. There have been many studies done in the past that show LLLT to be beneficial towards scalp hair growth. However, a large number of those studies have been of subpar quality (e.g., small sample size, bad photos) or biased (e.g., sponsored by a laser device manufacturer).

So this subject remains somewhat controversial. However, in the past month, three new studies have been published in support of low level laser therapy to treat hair loss:

  • A 2017 study from China concluded that low level laser therapy stimulates hair growth in mice via upregulating the expression of Wnt10b and β-catenin. Hair follicle count remained the same in LLLT treated mice versus untreated mice, but hair length increased in the former. If this holds true in humans, perhaps LLLT can really make existing hair stronger and less likely to die from the attack by dihydrotestosterone (or at least prolong the battle). However, long-lost hair is probably not going to return from LLLT.
  • A 2017 study from Iran tested a new laser scanner device (with a combination 655 nm red laser plus 808 nm infrared laser) by comparing it with a 655 nm red light laser hat. Both products led to hair growth benefits, but the laser scanner was superior. So laser wavelength may make a difference in outcome.
  • A 2017 study from Egypt on female hair loss sufferers found that combination LLLT+Minoxidil 5% treatment led to the better outcomes (measured via Ludwig scale classification and patient satisfaction) in comparison to LLLT only or Minoxidil 5% only treatments.

LLLT Wavelength: Blue Light > Red Light?

A 2017 study via a European collaboration effort found that a UV-free blue light laser (453 nm wavelength) led to hair growth via prolongation of the anagen phase of the hair cycle, but a red light laser (689 nm length) did not do the same. Update: February 2021 — From the same scientists, a new study on blue light, cryptochrome 1 (CRY1) and hair growth.

This result is surprising since most commercially available LLLT laser products (combs, caps, helmets) are of around 650 nm wavelength (i.e., in the red light spectrum). Interestingly, a 2015 study from South Korea found that 830 nm laser was superior to lower wavelength lasers (of 632 nm, 670 nm and 785 nm) when it came to hair growth in rats.

LLLT Light Wavelength
LLLT Laser Wavelength Spectrum.

The above mentioned European study also made an important finding: “We provide the first evidence that OPN2 and OPN3 are expressed in human hair follicles”.

Update: A November 2021 report finds that photobiomodulation response from 660 nm is more durable than that from 980 nm.

Update: A June 2021 report finds that blue light therapy is a promising therapy for patients affected by androgenetic alopecia. Moreover, blue light-emitting diodes seem to darken grey hair in some people.

Combining Fractional CO2 Laser and Hair Growth Factors

I discussed fractional lasers and hair growth in a post in 2015. Now a new study from China finds that a combination treatment using carbon dioxide fractional laser treatment plus growth factors is significantly superior to using growth factors alone.

Krox20 and Dr. Lu Le

Krox20 and Hair Growth

By far the biggest news this month was the story that scientists at UT Southwestern Medical Center in the US found that a specific protein in skin cells called Krox20 (also known as EGR2) turns on hair shaft progenitor cells and is therefore responsible for the initiation of hair growth on the scalp. Moreover, these same progenitors also produce a protein called stem cell factor (SCF), which the researchers showed is essential for giving hair its pigmentation. Full study here. The research team was led by Dr. Lu Le.

There were 100 plus headline stories about this in the global media, and at least 10 people posted links about this story in two blog posts from earlier this month or emailed me in person. I always appreciate hearing about groundbreaking new information, but I wish people would at least skim through the comments for links and make sure the story is not so obvious and widely covered!

Many of the newspaper headlines about this discovery screamed that the cure for grey hair reversal is near (note that this is yet one new approach among many that are being considered to reverse grey hair) and I have covered some of the main discoveries related to both grey hair and the link between skin cells and hair growth on this blog many times in the past.

The main researcher involved in this work (Dr. Lu Le) was actually researching a very specific type of nerve related cancer before stumbling on these interesting findings. At the moment, Dr. Le’s bio page does not even list hair loss as an area of clinical interest for him! However, for those who were paying attention, Dr. Le made one of the main presentations at the recent SID annual conference. His “state-of-the art plenary lecture” was titled:

“Progenitors that Create a Niche for Hair Pigmentation and Graying”.

These findings have yet to even be utilized in any kind of pre-clinical trials, so I was not too excited about this news story and did not write a separate post on it. However, it should be noted that Dr. Le has said the following (and will therefore likely add hair loss to his areas of interest soon):

With this knowledge, we hope in the future to create a topical compound or to safely deliver the necessary gene to hair follicles to correct these cosmetic problems.

Intravenous Immunoglobulin (IVIG) Therapy for Hair Growth

I got far more excited about a new study that came out a few weeks ago titled “The effects of hair regrowth with intravenous immunoglobulin (IVIG) therapy. Two case reports“. Several before and after photos in there that show moderate hair regrowth. The key quote that struck me was:

“A literature review did show two cases where treatment with IVIG led to hair regrowth in alopecia universalis. But there have been no case reports of patients with AGA having substantial hair regrowth with IVIG or other immune modulating or anti-inflammatory drugs. Until now.”

Of course the first thing that came to my mind was JAK inhibitors, since those have worked superbly on patients with alopecia areata (AA), an autoimmune disorder. Aclaris Therapeutics (US) plans to test topical JAK inhibitors on patients with androgenetic alopecia (no autoimmune component) in the future as long time readers of this blog know. Fingers still crossed on that one and hoping for the best, although I am disappointed that we have to rely on just one company (due to Angela Christiano/Columbia University’s sale of the key patents to Aclaris).

— Interesting new paper from Russia titled “Hair Follicle Reconstruction and Stem Cells“. Note that one of the authors is a Dr. Vasily Terskikh, who is not the same (as I originally mistook) as the far more famous hair loss researcher Dr. Alexey Terskikh. Most likely they are related since the latter is also from Russia and involved in hair research.

New paper from Dr. Claire Higgins and team titled “Methods for the isolation and 3D culture of dermal papilla cells from human hair follicles”.

— New study suggests benefits of low level laser therapy (LLLT) on scalp hair growth might have a scientific basis. They found that a 3.2 J/cm2 of 453 nm blue light exerts a positive effect on hair growth ex vivo. In contrast, hair follicle treatment with 3.2 J/cm2 of 689 nm light (red light) did not significantly affect hair growth ex vivo. Make sure to read my post on laser wavelength and hair growth.

And now on to medical items of interest:

An artificial womb successfully grew baby sheep. Humans would be next according to some. This surreal idea was also discussed in this video from last year.

The much anticipated skin gun is back in the news. Apparently, “RenovaCare is applying to the US FDA for permission to use it in routine clinical practice. It will then look to obtain a similar licence in Europe”.

Getting close to mass production of bones, organs and implants.

Type 1 diabetes cured in mice.

HIV eliminated in mice using CRISPR.

I am getting a feeling that everything seems to work in mice, including GW1516.

The most promising way to mental superpowers.