The Arrector Pili Muscle (aka Goosebump Muscle)

Update: August 7, 2020 — Yesterday, Taiwanese and US researchers published an important paper titled: “Cell Types Promoting Goosebumps Form a Niche to Regulate Hair Follicle Stem Cells.” The work was led by Dr. Lin Sung-jan of National Taiwan University. In collaboration with researchers from Harvard University (US).

Goosebumps, the Sympathetic Nervous System and Hair Growth

Lin’s team found that the biological mechanism behind baldness in men is closely connected to the sympathetic nervous system. Hair follicle stem cells activate after receiving signals via what are known as ADRB2 receptors. Based on these findings, the researchers hope to develop small molecule drugs that can activate ADRB2 receptors as a means of regenerating hair.

Goose bumps are a sympathetic nerve response involving the contraction of tiny muscles all over our bodies. These arrector pili muscles causes hair to stand up straight on the skin when we are fearful and under threat. The scientists aim to ultimately control the muscle-nerve system that drives hair regeneration. A video of these findings was published here. It is quite something to see Dr. Lin Sung-jan being mobbed by the media.

Goosebumps and Arrector Pili Muscle
Goosebumps, Arrector Pili Muscle and Hair Growth.

Jan 10, 2017

Several weeks ago, the arrector pili muscle got significant coverage in a few newspapers around the world. Famed Australian dermatologist Dr. Rodney Sinclair co-authored an important paper titled “The arrector pili muscle, the bridge between the follicular stem cell niche and the interfollicular epidermis” that was just published this month.

Dr. Sinclair has been involved in this area of hair loss research for a few years and already published similar findings several times in the past decade, including material on his own site. Nevertheless, Australian newspapers were especially interested in this latest study and its findings as evidenced by articles such as this one and this one.

The Arrector Pili Muscle

Arrector pili muscles are small muscles attached to individual human hair follicles on both the scalp as well as body (so we have millions of these muscles throughout our bodies). Contraction of these muscles causes hairs to stand up, a phenomenon that is known as goosebumps. Therefore, the musculus arrector pili is often referred to as the goosebump muscle.

Every hair root is connected to the arrector pili. This smooth muscle contracts in response to signals from the “fight or flight” sympathetic nervous system.

The Arrector Pili Muscle Degeneration and Hair Loss

In recent years, a few studies have come out that suggest a possible connection between the arrector pili muscle degenerating (where it gets replaced by fat) and hair loss due to the subsequent disconnection between various hair follicle stem cell populations. It is possible that an intact arrector pili muscle plays a crucial role in the maintenance of follicular integrity and stability.

However, there are many uncertainties about this theory that I discuss in the next section. It seems that while in alopecia areata (AA) patients the arrector pili muscle remains intact, this is not true in androgenetic alopecia (AGA) patients (and unfortunately over 95 percent of balding men suffer from AGA). So this could be why it is much easier to grow back hair for people with AA compared to people with AGA. However, the rate at which the arrector pili muscle degenerates and gets replaced by fat varies substantially between patients and between individual hairs on the same scalp. Some miniaturized vellus hairs in balding regions might even never lose most of their arrector pili muscle connection.

Points of Contention

  • According to Dr. Sinclair’s own quote from a past paper, “It remains unclear whether arrector pili muscle regression is a cause or effect of permanent follicle miniaturization“. I think this is the crux of the issue surrounding this theory/hypothesis.
  • It seems like hair that is transplanted from the back of a person’s scalp to the front of that same person’s scalp regenerates the arrector pili muscle. A very important related study from 2012 comes to us from Japan. So it might be very possible to regenerate this muscle.
  • In Dr. Tsuji and his team’s groundbreaking technology (hoped to be released in 2020): “the transplanted primordium also forms connections with surrounding tissues (arrector pili muscle and nerves) and repeats normal hair cycles”.
  • There are 100s of anecdotal reports on the internet of people regrowing long-lost hair in bald scalps. On the internet, you can find many reports of old men who recently started taking dutasteride for enlarged prostate issues and have subsequently noticed hair regrowth on areas of their scalps that have been totally devoid of any visible hair for decades. Maybe they regenerated their arrector pili muscles; or maybe those muscles always remained intact in spite of severe AGA; or maybe one can regenerate hair without the need for having any intact arrector pili muscles?
  • It is unclear when exactly we have a point of no return where the arrector pili muscle is largely or entirely replaced by fat and hair stops growing (either as a cause or effect — see first bullet point above). It seems like there is significant variation depending on person and hair follicle. In many cases, the arrector pili might not be entirely degenerated and replaced by adipose tissue even in areas of the scalp where one has been bald for several decades. In such cases, subsequent hair and muscle regeneration could perhaps even be possible via something like Dutasteride or Finasteride?

Dr. Takashi Tsuji’s Hair Loss Cure will be Costly

For those of us who have followed hair loss cure research over the past decade, the number one person of interest is Japan’s Dr. Takashi Tsuji. He previously announced the aim of releasing a hair loss cure by the end of 2020. This was prior to the onset of the current global pandemic. Dr. Tsuji’s work is occurring at RIKEN’s major research center in Kobe, Japan. And he is partnering with locally headquartered Organ Technologies and Kyocera.

Update: August 6, 2020

Dr. Tsuji replied to my email, and it seems like no new announcements in the August 5 presentation:

Dear Admin,

Thank you for your interest in our research. There was no updates because the lecture was for graduate school students aiming to get fundamental knowledge. For further information, please refer to our laboratory website for the latest news on the progress of our research projects. Our laboratory is striving to advance research with the aim of fulfilling the expectations to improve quality of life for many individuals. We thank you for your patience and continued support of our research activities.

Sincerely,
Takashi Tsuji
Laboratory for Organ Regeneration
RIKEN Center for Developmental Biology Research (BDR)

Update: August 4, 2020

Dr. Takashi Tsuji Zooming in August

By now, most readers know that Dr. Takashi Tsuji is participating in several Zoom and web based online presentations in August 2020. I have sent a few messages to Fuji Maru and to ハゲリーマンちゃんねるin case they can attend any of these events. I will update this thread if they or others send me any new information.

Dr. Tsuji will be presenting via a Zoom conference on August 5, 2020 (h/t reader “Karl” and “RolfLeeBuckler” on HLT):

Then, on August 24 and August 25, Dr. Tsuji and RIKEN will be making a  two-part web presentation.

  • Part 1 = “Of hair science front line: from the basics of innovation to beauty and health.”
  • Part 2 = “Overview of new products for FY2020.”

Also keep an eye on RIKEN’s Facebook page, and on Organ Technologies’ website.

Takashi Tsuji Web Presentation
Takashi Tsuji Web Presentation on August 24 and August 25, 2020.

Update: June 26, 2020

Dr. Takashi Tsuji New Interview

Recently, a number of readers have asked about Dr. Takashi Tsuji’s January 2020 article and interview in a Japanese magazine. Earlier today, reader “Lurker10” managed to purchase it from here and also posted it on Imgur! Keep in mind that all the information in this article is from prior to the Covid-19 pandemic. So there could be some delays in the work’s progression. Update: It seems like the interview mostly covered Dr. Tsuji’s historical hair loss research related work per reader comments and translations.

Dr. Takashi Tsuji in 2020
Dr. Takashi Tsuji in his lab in 2020.

Baldness will be Extinct

Update: August 14, 2019 — English version of below video is now published. Title: “Baldness will be Extinct! The Time has Come!!”

July 22, 2019

In June 2019, Dr. Tsuji gave some interesting quotes to the Financial Times about the future importance of Kobe when it comes to medical tourism. Also in June, Dr. Tsuji gave an important 4 page interview to Beyond Health.

Dr. Tsuji: Hair Loss Cure in 2020 or 2021

Recently, a Japanese hair enthusiast named “Youngjet” posted a video regarding his attendance of a recent lecture in Japan by Dr. Tsuji. Five people emailed me or commented on here about the below video!

After you translate the video, it seems like Dr. Tsuji will release his cure in 2020 and/or 2021. It will initially cost 20 million to 40 million Japanese Yen ($190,000 – $380,000 per today’s exchange rates). Prices will then slowly come down over the next decade.

Perhaps Dr. Tsuji gave us two numbers (20 million and 40 million) because some people will have one session and some will have two sessions?

Note that as of 2019, they are already testing this treatment in humans. Favorable Japanese regulations probably allow for this possibility, even though clinical trials are yet to be completed.

Make sure to see the results of my 2016 poll on how much you would pay for a hair loss cure. Only 12.5 percent of you voted for over $100,000!

— The guy (“Youngjet”) in the below video has the following Twitter account.

— Another Japanese person named “Tonegawa” has more information on these developments.

Perhaps the most important screenshot from the above video:

Hair Loss Cure in 2020 or 2021.

Hair loss cure news blog. Hair cloning and multiplication for baldness. The latest news in hair regeneration treatments for androgenetic alopecia.