JAK Inhibitors Show Great Potential as a Hair Loss Treatment

Angela Christiano is up to it again, and the online hair world is very thankful.

It was just a little over a year ago when the internet was ablaze with the news that Dr. Angela Christiano and her colleagues were studying the pharmaceutical drug ruxolitinib in cases of alopecia areata. Like tofacitinib, ruxolitinib is a type of drug known as a JAK inhibitor. First, the studies were done on mice and showed successful hair growth. Those studies were then followed up by a pilot trial involving 12 human subjects. The results from the human study were significant. As you can see, several subjects were able to regrow full heads of hair. That was pretty exciting news at the time, although, these results were found in cases of alopecia areata which is different and much less common than regular “pattern baldness.” Alopecia areata is an autoimmune disorder in which the immune system attacks hair follicles. Still, this study raised the question of whether this treatment could be helpful for those experiencing common hair loss.

Topical is the way to go

On October 25, 2015, Dr. Christiano and colleagues released the documentation of their latest research “Pharmacologic inhibition of JAK-STAT signaling promotes hair growth.” This time they were testing topical formulations of the JAK inhibiting drugs, tofacitinib and ruxolitinib, as a treatment for adrogenic alopecia or “common” hair loss. The results of this recent study showed that topical applications were even more effective than the former study which involved oral administration of the drugs. There’s a lot of information dispersed throughout the multiple media articles which have been written, the scientific article published by Christiano & her peers, and the multiple videos which were released about this study. I’ve highlighted the proceeding facts to give the most insightful view of the implications of this research.

Many of the articles online have highlighted the trademark photograph of the three mice side by side demonstrating the hair growth effect of the JAK drugs. However, if you carefully examine the scientific article published by Christiano you will also notice these photos which depict human hair growing on human skin grafts which were placed onto the backs of mice.

Basic RGB


You will also notice the photos at the bottom titled “Human DP Spheres”. In these experiments, human dermal papillae cells were cultured in 3D environments and the JAK inhibitor drugs were added to the cultures to see what kind of effect they would have on the hair follicle growth process. Check out that tofacitinib photo, quite impressive. See “Joseph’s Thoughts” later in this article for a potential application of this treatment approach. Hint: Rapunzel.

Dr. Christiano mentions in one of the articles online that “The surprise was when we started using the drugs on alopecia areata patients, when we used them topically the hair grew back much faster and more robustly than it did orally.” That means that topical JAK inhibitors have already been tested on humans. Another article mentions at the bottom, “It remains to be seen if JAK inhibitors can reawaken hair follicles that have been suspended in a resting state because of androgenetic alopecia (which causes male and female pattern baldness) or other forms of hair loss. So far, all the experiments have been conducted in normal mice and human follicles. Experiments to address hair follicles affected by hair loss disorders are under way.” The wording of that paragraph leads me to believe that Dr. Chrisiano and colleagues have begun pilot studies testing JAK inhibitors in humans with androgenic alopecia, which is of course, a good thing.

These fascinating JAK inhibitor drugs have a multi-faceted effect on hair follicles. Here are some descriptions of their method of action from the published study:

JAK inhibitors stimulate hair follicles out of the resting phase into the growing phase. They also show the ability to elongate the growing phase.

JAK inhibitors activate the Wnt and Shh signaling pathway.

JAK inhibitors cause the activation of hair follicle progentior (stem) cells.

Tofacitinib (a JAK inhibitor) promotes inductivity of dermal papillae cells.

Tofacitinib promotes hair growth by positively affecting genes within pathways that are crucial to hair growth. For example: TGFB pathway genes, BMP pathway genes, LEF1, and NOTCH pathway genes.

As a bonus aside, the scientific study also depicts results from using a “Sonic Hedgehog” pathway agonist. It is listed as SAG and depicted in the study’s photos. The hair growth results from using SAG appear very good, but not quite as impressive as the JAK inhibitor drugs.

Joseph’s Thoughts

I always enjoy this part of the article. It’s my opportunity to shed light on these subjects in way that is not found in any other article or forum topic you might find. This latest JAK inhibitor news happened to be particularly stimulating because the findings within it related to several other topics in the hair science world. Let’s check it out.

So, let’s get this straight. Dr. Christiano and others originally tested out these JAK inhibitors drugs in mice and noticed significant hair growth, then they tested the JAK inhibitor drugs in humans and noticed significant hair growth. Is that substantial supporting evidence for the validity of the familiar mouse/prelinical testing model? I’d say yes it is. I hope that can bring some peace to the internet hair enthusiasts.

It might be a good time to go review the article I posted about  Follicum’s preclinical studies with fresh eyes. Those results were found in mice and are quite impressive. Like Christiano, Follicum also tested their drug on human skin grafts.

This is more of a curious thing, but I had to notice that Dr. Christiano is definitely marketing her hair research to the ladies. The latest barrage of articles mentions that Dr. Christiano has patented the use of JAK inhibitors for hair growth and will be commercializing them through her new company Vixen Pharmaceuticals, Inc. . Earlier this year in a NY Times article it was mentioned that Dr. Christiano was also co-founding a company that is developing a cellular based treatment for hair regeneration using cultured hair follicle stem cells. The name of that company is Rapunzel. That would make two decidedly feminine aliases for her hair tech ventures. It’s fine with me as I am quite certain that the technology itself is applicable to both men and women. One more thing, Dr. Christiano has been involved in hair research for a long time. If she is creating a pharmaceutical company to bring forth hair growth treatments, there is a very good chance she has other drug candidates in mind beyond JAK inhibitors. Cha-ching.

How does this research relate to other hair growth treatments that are being developed right now? As I said in this article, topical is the way to go. If you thought it would be a good idea for Kythera Pharma to develop a topical version of Setipiprant at some point, this latest research definitely validates that sentiment. Today, I happened to revisit Cotsarelis’ research on PGD2r inhibitors and hair growth (the research that was essentially licensed to Kythera). I was reminded that he was using a topical version in his mice studies. Now, this latest JAK inhibitor study brings forth great evidence that topical delivery is the most effective method for growing hair. I’ve got a feeling that the good folks at Kythera are aware of that and are also working on a topical version of Setipiprant.

As I’ve said before, the people working on hair growth treatments may be very quiet, but that doesn’t mean they are idiots. They know the way to get this stuff done. There is undoubtedly a lot of good things to look forward to.

Lastly, I want to thank Dr. Angela Christiano for her beautiful presence in the world of hair regeneration research. It’s very nice to watch her discuss her findings in some of the videos that have accompanied this latest development.

Until next time, be well.


76 Comments on “JAK Inhibitors Show Great Potential as a Hair Loss Treatment

  1. Good breakdown. I believe the benefit of these drugs are using them in dr christiano’s 3d spheroid method. Hopefully we get more info from congress about rapunzel.

    • Thank you Renee. I agree that the use of JAK inhibitors or other drugs in the 3D culturing model is exciting! It’s also something I had not considered.

    • Hi Sammy,
      Thanks for the comment. This treatment is not readily available for hair growth right now. I am not selling it. However, in due time Vixen Pharmaceuticals should be selling it for hair growth. I am not sure when that will be, if you follow this blog I will surely post news about its release.

    • Hi S Dey,

      You would have to contact your doctor about using the JAK inhibitors mentioned in this article, and perhaps would want to wait a bit until more studies have been conducted by Dr. Christiano and co.

  2. What are the known side effects of tofacitinib? Has that been mentioned yet? A quick google search provided me with the following side effects, but I am wondering if they are the same for the topical version.

    fever, chills, tired feeling, night sweats;
    stomach pain, loss of appetite, diarrhea, weight loss, or a change in your bowel habits;
    pain or burning when you urinate;
    body aches, sore throat, flu…

    • Hi Josh,
      Thanks for your inquiry. As of now we do not know what common side effects, if any, will be associated with topical administration of tofacitinib. Scientificially, it is theorized that side effects would be grealty decreased through topical use since the drug does not go systemically.

      By the way, I just google searched for Penicillin, which is of course the most common antibiotic that medicine has been using for about 70 years. (This does not mean I’m an advocate for Penicillin) The search showed very similar side effects to the ones you have just mentioned.

  3. I have read studies about the dangers associated with JAK inhibitors and its effect on cholesterol.

    I don’t want to set my hopes too high with these new findings, but Dr. Chrsitiano’s recent announcement seems to be the best hope for a cure. I just hope we don’t have to wait 5+ years for the drug to hit the market.

    • As always it’s important that we observe these new findings and keep safety as the number one priority before considering their use.

      I believe there will be several cellular based hair treatments coming with no known side effects that may better suit your interests.

        • No not really, Josh.
          I was thinking more the likes of Replicel, Histogen, Rapunzel, Shiseido, or Theracell.
          You can check out the Ultimate Guide to Hair Regen post on this site to read more.

  4. Dear sir/Madam.
    I m suffering for hair problem.i sew ur add from Facebook. And I empress too much.so I will be agree for grow my new hair.pls advice me for how to contact u .And I m General employer in Singapore. So pls add the details for rough costing for new hair grow or hair transplant.

    Thanks and ur best regards
    I wait for ur better reaply.

  5. Hi
    If these drugs work on human scalp does take FDA approval, which this drugs already have, will take several years or there is a shorter way to this drugs coming sooner.
    Thank you

    • Hello Aidin,
      Thanks for the question. I believe that since Tofacitinib is already FDA approved, someone like Dr. Christiano would be able to start at the Phase II trial in the process of approving the drug for hair growth. I am not certain, but it is what I’ve heard in other situations. We will probably have to wait a little bit before we get a confirmation on that info as sometimes researchers like to keep things quiet for a bit.

      • Someone with more time on their hands with a greater curiosity on the regulatory path/timeline might want to look at the same for Minoxidil. Virtually the same situation, pill was used for high blood pressure and found it grew hair. Upjohn them had to run it thru the FDA. It was about 30 years ago, I’d know as I was using a 2% compounded topical off label before it was approved at that strength as an RX only drug.

  6. How likely is it that these drugs will be effective for male and female pattern baldness?

    • Hi Sam,
      It is looking very likely indeed, based on the results that were presented in this article. We will follow the news results as they are released from Dr. Christiano’s office.

  7. Is there any rough estimate on when a JAK topical inhibitor will be available to the public? Also, what is the likelihood of the drugs effectiveness against MPB as opposed to AA based on preliminary studies?

    • Hi Nick,
      A rough estimate at this point would be just a guess. It could potentially take up to 4 years. However, as other people in this thread have mentioned, there is a potential to use the drug Tofacitinib off-label compounded into a topical solution. My feeling is that it would not be quite as effective for MPB as what it has shown in AA (those results were remarkable). But, if it grew hair we would all be happy, yes?

  8. Additionally, does Vixen Pharmaceuticals have a website? I can’t seem to find one and would like to read more on the development and eventual planned release of the drug?

    • Vixen Pharm does not have a website yet. I will definitely post updates on Christiano’s work and Vixen as they come.

      • Hi,
        Do you think that this could also work for people they have already lost their hair follicles for example by scarring alopecia?
        You mentioned that tofacitinib promotes hair growth by positively effecting of genes within pathways. Does it mean that jak could even grow new hair follicles?
        Thank you.

        • Hi Num K,
          Based on what I’ve read from the studies, it looks like JAK Inhibitors could be useful in all situations. I’m not sure if JAK could grow new hair follicles, but perhaps awaken hair follicles that were not visible beforehand. We will have to allow Dr. Christiano and company to provide definitive answers for all of our important questions.

  9. To all of the readers who have enjoyed this post and have important questions about this subject on their mind:

    First off, I’d like to say thank you very much for your support of this website. In regards to all of the insightful questions that have been inspired by this research I will say that it is important to remember that all questions will be answered by the right source at the right time. Until then, it is best to be thankful that this work is being done and have as much patience as we can. The promise of this research is something to stoke the fires of hope. This work is in the company of so many other great works that are being done to create hair regeneration technology. When it’s time for us to know more, we will know. Trust.

  10. Hi,

    I am from India and willing to use this JAK Hair Solution, can you please provide the details of whom to contact, where it will be available and what will be price.

    Thanking you,


    • Hello Raghuveer,
      Please refer to my response to Nick’s first question a few replies above. You would need to contact your doctor to see if your doctor approves of using Tofacitinib and compound it into a topical solution.

      Best Wishes,

  11. what about follicept( low-dose IGF-1 is the ideal physiologic way to stimulate hair regrowth) ? what happened to the company? Any soon release? anu results?

    • Hi Fadi,
      Follicept still has their website up and is intending to release the product. I believe they have said they are awaiting approval from the FDA to release their product as a cosmetic. I believe if Follicept is going to be effective at growing hair, Dr. Hsu still needs to figure out the amount and frequency of dosing.

      • Hello follicle
        What is your thought about siu wound healing hair regeneration?

        • Hi Yoda,
          It looks good. I would assume it is much farther off (as far as timeliness) than other treatments. For example, the treatments I have listed in http://www.folliclethought.com/?p=69

          Replicel and Histogen are both happening very soon.


          • I believe histogen is not a cure and replicel will be available in 2018 if it is work, I believe samumed will reliese the sm very soon as i can see for their fast trials. but i believe this wound healing protocol is very promising and easy aplicable if it works. thank you follicle thought!

          • Histogen has shown as much promise as any other treatment I’ve seen, if not much more. With multiple injections over longer periods of time, the results would apparently be even better. Replicel has already shown significant growth % increase in multiple people, and their process has improved since that first trial. When we get to see the results from Samumed, it will be a good thing. Thanks, Yoda.


    • Hi Fadi,
      I’m not sure actually, I do not use them. I believe members of a hair forum could help you out in this situation.

  13. why do not scientists take the miniaturized scalp hair follicle from a bald person scalp and study it alone and make thier researchers directly on it and try to develop it to a new normal hair follicle using different medications and procedures?

    • Hi Fadi,
      I believe that follicles taken out of a human scalp would have a short window of life after being outside the body. I do know there are at least two teams who are developing human hair follicles for testing purposes in vitro. Those would be Dr. Lauster’s team at Univeristy of Berlin and the IBN in Singapore http://www.folliclethought.com/?p=173.

  14. Would you know if Dr Angela Christiano is doing any human trials???? If so how can we be a part of it?

    • Hi Sheila,
      I have not seen Dr. Christiano promote a human trial for the JAK inhibitors, though I do suspect that she is engaging in them. Because she is keeping it quiet, I am sure the trials are small and I do not think she would be accepting volunteers. Though, if this trial goes well, I’m sure she will be creating a larger trial for her new company Vixen Pharmaceuticals to go through the FDA process. That will be announced in the future so if you stay in touch with this blog you will surely be aware of it when it is occurring. If any inside information about trials etc. comes my way I will keep you in mind and let you know for your daughter.

    • Hi Zaheer,
      If this treatment gets approved in US, you can definitely expect it will make it to India. We do not know when it will become available, please refer to previous 6 or 7 comments in this thread. Perhaps in a few years it will be available.

      • If you’re asking how much time you can expect before it becomes available to you, we do not know for sure. Perhaps 2.5 years?

        • That much of time is too late sir i already lost 75% of hair but my scalp shape is same and their has very small and slight hair is their 2 years means i lost completely

          • Have faith, my friend. Better things are coming.

  15. I suffer from ankylosing spondiltis and alopecia universalis. Is the drug Tofacitinib available for treatment of spondilitis? Do you know if its possible to be involved in research of the drug?

    • Hi Melissa,
      Thanks for stopping by and sharing a comment. I think the question of using Tofacitinib would be a great one for a local dermatologist or your primary care physician. To be honest, I don’t believe the chances are great at being involved in the research of the JAK inhibitiors currently, since the study groups are quite small. If you stay tuned, I believe Dr. Christiano will be looking to create larger clinical studies in the future.
      Well Wishes,

    • Thanks Prakash, if you subscribe to the blog at the right sidebar you will stay updated on all news.

  16. can I use the compound to make my own topical solutions. I live in India.

    • Hi Ameena,
      You’d have to talk to your medical doctor or dermatologist about that.


    • Hi Carlos,

      Thanks for your question. Please review other responses in this thread. It is unclear when this product will be available. Perhaps 3 years.

    • Hi Prashant,

      A good route would be to contact your doctor or dermatologist.


  17. It is really true that Jak Inhabitor really work as we hair loss Sufferer always wanted.If it really true then when it will be came to the market.I live in kolkata(India).So how much we have to spend for buy this products and How much time we need to use for permanent cure from androgenic alopatia.Hope we will get the right solution soon.

    • Hi Arjit,

      Like the other responses in this thread, we don’t know for sure when it will become available. We have to look towards a new update. Perhaps 3-5 years.

  18. I hope this doesn’t get applied like Rogain or it will be a mess for people of diffuse hair loss!

    • Having the opportunity to use such a product in any application would be a complete blessing, Yes?

  19. DEAR sir
    . Is this medicine 💊 available in Hyderabad,India?
    Can I usage this medicine 💊 directly without any doctor advice.

    • Hi Mohd,

      I do not know if the medicine is available in Hyperabad. As I’ve repeated in this thread that is something you could ask a doctor about.

  20. I guess you are right but when using in a liquid or foam .. Similar to Rogain, the application for people with a diffuse hair loss makes it extremely difficult to apply and reap benefit… Btw do you know if Dr Christiano is accepting any young women for trials??? I’ve tried to get in touch with her for the past 6 years, to no avail.
    Sheila Mizrahi

    • I understand what you mean. Hopefully, however this product is applied it will produce meaningful results that improve people’s lives.

      I don’t believe Dr. Christiano is recruiting anyone for trials at this time.

  21. Hope you get this drug very soon to the market, I’m dying every second of time to get this drug since I heard about it.

  22. My son (16 years) has Alopecia. He has no hair on his head (well, he grows a bit from time to time, but it does not last long) and no eyebrows. Would LOVE to have him try this. Is it available topically at this point?

  23. Hello, Follicle Team,

    I really want to thanks and appreciate your work around.

    Your topic and finding risen our hope & concern as we knew Unfortunately, the vast majority of men (and many women too) who have hair loss suffer from androgenic alopecia, also known as male pattern baldness (MPB). JAK inhibitors still did not shown any potential result on MPB this meant this NEW finding only work for only 1% people who suffering Hair Loss due to Alopecia Areata (AA).

    Do you aware of any new finding or result that cure MPB and such Re-growth hair that fallen long year back ago ?

    I reached to this conclusion JAK inhibitors still take more than 2.5 or more years.

    Your response will be appreciated,

    • Hello,

      JAK Inhibitors did show potential for MPB which is why Aclaris Therapeutics bought the rights to develop that treatment. Search this blog for Aclaris. Besides that take a look at the Ultimate Guide to Hair Regeneration for the closest cures out. I am working on it this week.

  24. Thanks Team,

    It means we are very close to win the battle of Hair Loss/Baldness very soon!

    If i not bothering you can you please summarise what are the ‘%’ re-growth result on all above disscussed Medicine? are they also effective for frontline baldness?

    Thanks & Regards,

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