Kenogen: A New Phase of the Hair Cycle?

Earlier this month, an interesting new study was published in the Experimental Dermatology journal by UK based scientists. The title of this study was “Hair regrowth in male and female pattern hair loss does not involve the conversion of vellus hair to terminal hair“.

Kenogen Hair Follicles

Basically, the scientists found that when medications such as minoxidil, finasteride and anti-androgens were used to treat hair loss patients (both men and women), the resulting hair regrowth was almost entirely attributable to the reactivation of dormant non-vellus hair follicles (termed as “kenogen” hair follicles) rather than the conversion of fine miniaturized vellus hair into thick terminal hair.

This is a very surprising finding. In both male pattern hair loss (MPHL) and female pattern hair loss (FPHL), terminal hair miniaturizes via shorter and shorter growth cycles. Finally becoming vellus almost invisible fine hair. I am pretty certain that it has long been assumed that hair loss medications cause some of these vellus hair to become terminal hair once again. However, this latest study suggests something entirely different by concluding that:

We would propose there is a population of growth restricted (dormant/kenogen) non-vellus hair follicles, which are re-activated by effective medical treatments as an explanation for the increased hair growth observed in FPHL and MPHL. Our findings have a fundamental impact on the pathophysiology of hair changes occurring in patterned hair loss.

Hair Follicle Growth Cycle and Phases

We have all heard of the three main phases of the hair follicle growth cycle in anagen (growth), catagen (transition/regression) and telogen (resting). There is also a lesser known phase called exogen, which is when hair follicles undergo shedding. Also see my post on telogen effluvium.

However, I had never heard of this new kenogen phase before. A basic google search showed that while this phase is almost never mentioned in literature, it was discovered as early as in 2002 when a study titled “Kenogen: A new phase of the hair cycle?” was published in Italy.

I am not sure if just several studies on this are sufficient to make any conclusions, but it is hard to believe that there could be some follicles in a dormant state that were previously unaccounted for and that are being reactivated by hair loss medications.

87 thoughts on “Kenogen: A New Phase of the Hair Cycle?”

  1. @cratusg, Think about the thousands of balding men roaming the inter wide webz for a cure each day. Dont you think it would be a hot topic if it did anything? It reeks of scam.

  2. Very interesting findings. The more findings that come out about hair, the better.

    Also @Admin, a member of HLT got a response for Gail Naughton of Histogen. She says that phase three clinical trials are scheduled in Mexico for May/June time frame, and that more info should be available in April regarding the trials.

    Source: Poster jc3303

    Unlike Minox/Fin apparently, Histogen does claim to bring back vellus hairs.

    1. Yep, there you go. 6 months to a yr phase 3, data collecting, marketing….2019 at the earliest.
      Are all medication development cycles so plagued by delay of just hairloss?

    2. Yep, there you go. 6 months to a yr phase 3, data collecting, marketing….2019 at the earliest.
      Are all medication development cycles so plagued by delay or just hairloss?

    3. Good lord. That thread gets heated really fast. Once there is a confirmation that phase 3 has been initiated, I’ll be popping a few bottles for celebration. Most likely beer bottles but you know… Also, that would be a great indicator for those worried about costs… Start saving about $25/ week (roughly 4 to 5 beers or 1 night out) and you should have enough to be able to get the treatment in a couple of years.

      ps. @ThatGuy – don’t get too caught up over on HLT… we have Histogen haters here too. I know it can get depressing when everyone things that the house will be on fire forever. Even if all Histogen does is maintain for 3-5 years, with 2 visits to the clinic, that would be a game changer for most of us including myself.

      1. Ha, thanks for the shout out.

        People are overreacting. The treatment is a year and some change away; right on schedule thus far. The results they had in phase 2 were great and apparently each round of HSC is like, 4-5x as potent in the final product.

        I’m not really worried about going bald anymore. With the things coming out over the next two years plus a transplant (worst case scenario) I’ll be back to NW1 at age 25-26.

        1. Kind of my thoughts. A boatload of effective treatments on the way within the next 3 years. By 2020 we should be able to get non-AGA-effected hair stem cells greatly multiplied which essentially amounts to a cure with an unlimited donor amount of hair.

        2. @ThatGuy
          I didn’t realize you were so young and it sounds like you are only a NW2 at most, although I could be wrong.

          I just got a Facebook “memory” from 8 years ago (age22) and I could see that I was already starting to move on from my NW2, which amazed me. I always considered around 6 years ago to be when I was starting to lose it, but really thinking about it, that was just when I noticed. So looking closely I can say that it has taken about 6-8 years (I think I fully/ completely became a NW3 this year) to move 1 position on the norwood scale, which is surprising and good news to me.

          I can’t say that your hairline will move at the same pace as mine, nobody can tell what the future will be for any of us but I will say this: When I first noticed my hair loss I went into a panic. I thought about what I would look like by the age 30 and I was convinced that I would be a NW 5/6. It scared the shit out of me. But the funny thing is, although I convinced myself that I was losing ground daily, it just wasn’t true – it was a slow yet cruel process just to move 1 NW in that time. The thing is… something happened in that time as well and while we can’t assume anything in regards to our hair, we can assume this (for most of us): In that time we gain perspective. I know that isn’t comforting right now but once you have that perspective your hairline really does become something you worry about less, not always but you will start to care less about it. Also with perspective you will see that, whether you can have it or not, a NW1 hairline might not be what you want. One of the great things that my NW3 has given me is that I actually look my age now, still young and youthful but also manly and knowledgeable (stroking my own ego right?).
          I guess what I’m saying is: if I had the chance today I would definitely get some of my hair back but going back to a NW1, I feel I would look weird and may lose some of my attractiveness. And while I would prefer not to lose my hair, I wouldn’t trade it for the experiences, perspective and calmness I have today. I have a job where I can live anywhere in the world that will have me (freelance), I travel pretty much whenever I want, I have my own little art studio and I have a partner that, while she is relatively new to me, is a sweetheart. If somehow hair isn’t in the cards for us, I can live with that, which is important for me to keep my peace of mind, but that is because I am living a life worth living.

          You seem like you have a good head on your shoulders. I know you are worried about how you are going to pay for the treatments when they are available, but understand that you are still super young in many aspects including financially. Start your career soon and focus on what makes you happy besides your hair… you will start to see that $25,000USD (even if you are making CAD) really isn’t all that much money in the long run.


          1. Wow, thats a similiar way i look at this.
            I think if i wouldnt loose my hair i would be another man. Life (at the time) would probably be easier, but this would lead to weaker me. I would probably chase too many girls and party too much;). Now im rich and very knowledgeable. I’ve developed skills that were needed to survive and made me interesting human beign. I wouldnt change that, Im happy.
            If there will be some treatment for hair loss, thats great! For me and a lot of you guys. If not.. so what? There are so many things in world to do than worry about your hair.

  3. Its no wonder that ppl have their doubts bout HSC. Histrogen is riddled with unanswered questions, dubious photo material, and last but not least delays. Just like every other company in the hairloss industry.
    Imagine when one of the many companies finally come forth with rock solid proof and a release date for their product:-0 The hairloss forums will explode:-D

  4. Another note in the 3d skin spanish company:
    “The next step we are investigating is to address the generation of these structures that are not continuous, but are in specific positions of the skin. We are still studying it, but we have indicators of how to produce things that we could not do manually, like Sebaceous glands or hair, ” says Jorcano.


    1. Looks like another scam product… look up Bosleys hairloss shampoo and it has some of the same Ingredients lol nothing to get excited about

  5. Hope that product will not just shampoo or conditioner…


    Can you tell there was one treatment named RISUG was developed in india, IIT KHARAGPUR. Whats its status??

    Great blog and tremendous efforts.

    1. Yeah I wish alexey would just team up and sell out with tsuji Shiseido Hairclone or something get in with big money and up their insight

  6. so this just in – Kythera/Allergan setipiprant trials at Wake Forest NC – they just emailed me if I want to be in the trial. I’m not going.

    40% go on Seti 40% on placebo and 20% on Finesteride. I’m not even going to risk 20% chance on taking Finesteride. Nope not me.

    You can see the PDF – I’m not allowed to share it. Commences next month.

    187 people testing..KYTH-105 6 MONTHS LONG

    you may
    experience the following risks which were identified in 569 subjects who received 1000 mg of
    setipiprant in previous clinical trials:
    • Asthma: 6 (1.1%) of study participants experienced
    • Headache: 15 (2.6%) of study participants experienced
    • Nasopharyngitis (inflammation of the nose and the part inside your mouth where the
    passages of the nose connect to your mouth and throat): 3 (0.5%) of study participants
    •Shortness of breath: 9 (1.6%) of study participants experienced
    • Diarrhea: 7 (1.2%) of study participants experienced
    • Upper respiratory tract infection: 4 (0.7) of study participants experienced
    • Nausea: 5 (0.9%) of study participants experienced
    There may also be other risks to septipiprant that are unknown

    I thought this would be of interest to admin because there was a recording of Kythera Agent years ago about this.. phase 2 or 3? They are still spending money to push this forward. I wonder what the before and afters look like and if it would be used in conjunction with RAIN….

    1. I would love to see a few pics of actual successful results. If they showed a few pics I bet people would be knocking down their door to be a part of their trial.

  7. Histogen is like that girl you meet, get her number and she just keeps postponing the first date. She will tease you with pics via text but will never actually meet up with you. Histogen don’t be that girl!! Start the freaking trial in may and deliver already. You should have been out I’m 2015 like you had listed in your website.

    Setiprant sounds like it has some bad side effects. Asthma and diarrhea. Sounds worse than ED. Better to not get it up than crapping your pants and asthma attacks in bed lol

    1. Lol… Asthma and Diarrhea are wrose that ED? Shit man, I sometimes have both together and I wouldn’t trade them from ED. One puff of my inhaler and eating right doesn’t even come close to comparing the idea of sitting on the end of a bed and having some girl rubbing my back asking me what’s wrong.

      PS… did you ever learn that when you start ignoring that girl is when she starts chasing you? Just sayin… It’s all about who needs more attention.

    2. Some of you people are ridiculous… you’re complaining about these side effects? Why dont you look at any normal pharmaceutical drug and see that many of them have internal bleeding and even death in them

  8. histogen is creating a treaatment that is based on regenerative medicine, and it does not work only on hair loss, they have other issues to work on, do not forget they are doing a good job with in cancer treatment ALSO.


  9. There will be cure one day for sure and I expect something from people like Tsuji and Angela. Histogen is a big time fake company and anyone with common sense can tell that. The reason they are not releasing anything bcos they don’t have anything… She is just stalling time for investment and then she will just go quite and Iam pretty sure about that.

    1. Yeah well seeing her videos of her presenting at conference with representatives like Bayer there tells me differently

  10. Wish I was a billionaire and I would have come up with a artificial solution which looks more better than natural and is permanent not like a toupee

  11. @Farhan: let me tell you this.. no one is releasing aything because no one has anything… billions are pouring into research every year. I would say patience is virtue..
    and every ever forget hairloss is not a problem of last decade. we have it since Adam and Eve… so be REALISTIC

    question: it is possible starts the trials in 2017?

    answer: Yes, it of course depends if anybody is interested in investing money and brining the technology to the clinical trials. However the most important thing to consider is the time it takes for approval of a clinical trial as well as the approval for the necessary GMP manufacturing of the transplants. So a start in 2018 is more likely.

  13. @Mike, thank you for the link. Very interesting link indeed. @mjones, now that we’ r talking about a tease…check out the picture in the link @Mike posted:-D

  14. I’m not happy about an empty box with dermatologist being recruited etc.

    I want to see proof of 100 hairs per square cm
    I want to see proof of the quote and proof of picture

    1. I don’t think everyone will get 100 hair in cm2 and it all depends of how you react to the medication. Same thing with the big two not everybody gets good results. Am saying this even though am one of the biggest fan of follica

  15. Mjones where did it say 100 hairs per square cm?

    Google Image 100 hair grafts per square inch
    It doesn’t matter how u respoND even 25 hairs per square cm will look amazingly full

      1. I know, this was from 6 months ago mjones said Follica says they can grow 100 hairs per square cm I just want mjones to link me to that quote I can’t find it.

        If it’s true that is a Norwood 0 cure

  16. I am 21, my balding is getting more and more visible. I was so hyped on Brotzu, but it went out. Will I be called the bald guy, or will these scientists somehow prevent my balding? I may need something by 2018, after that I am a bald man. What do you guys think? I don’t want to lose hair now and regain it later, I don’t want to lose it at all.

    1. same here brother, i am turning 20 this September but already had noticeable temple recession, can’t deal with this anymore.
      2018 may turn out to be an amazing year.
      but what we need is update and confirmation that these companies are doing their work otherwise it’s so difficult to stay positive.
      Replicel has been giving updates and that’s a good thing.
      But what happened to Histogen can anybody please contact them , we don’t even know whether they have started their trials in Mexico or not.
      I am not asking for updates every month but twice a year at six months’ gap we should reach out to them as an organization to keep track on their progress.
      It’s a high time to contact Histogen now and we must also inquire about Tsuji’s pre-clinical status.
      Admin can you do that for us?

      judging by the current scenario, this is order of release date of various companies-
      1. Follica (Q4 of 2017/2018) there is a good chance that it ends up in minoxidil like result.
      2. Replicel (2018/Q1 of 2019)
      3. Histogen (2019+) *they are delaying as * Rem.- they first showed photos in 2009 still the product is hidden in the bunker
      4. Brotzu (2018+) don’t even consider this product, they are not even sure whether it works on AGA or not.
      5. Tusji (2020+) they haven’t started trials yet.
      6. TissUse (God knows when they haven’t stated any timeline)

      and yes forget about kelopsia also. It won’t stand any chance in this competition

      we should make a group in this blog and make inquiries as an organization instead of doing it individually.
      Are u guys Up for this?

      first target histogen then tsuji.

      1. Oh the memories, im turning 27 this year and remember when I was 18-19 they said a cure would be here 5-10 years…it’s getting close to the upper end of that BS but we’ll see.

  17. i remember the days when fin got promoted over online forums for the first time, it was around 15 years ago. it was all hyped and everything.
    somehow I believe cure is not a pipedream and never come true…

  18. Can someone please TELL me the hype about Replicel?
    Quote: 70% of the people treated saw an increase in hair density of 14% in six months, this is what Rogaine and Propecia usually offer after 1 year of consistent use.

    is this good? did anyone grow hair after using fin or rogaine? it all seems like expensive flight tickets to Japan just for maintenance and also for lucky 70%?
    I am just so disappointed after seeing these figures… any treatment which doesnt offer NW maintenance is just down the hill and should never make it to the market. I am pretty sure 1-2 years after Replicel on the market, people will start bitching about it… seriously results are not better than fin or rogaine….

  19. Resukts may be similar to rogaine or propecia HOWEVER a treat ment without rogaine and propecia side effects in my eyes is a winner!

    1. Follicum sounds good but they are trialing their hair inhibition drug instead of regrowth drug. So that gives me a bad feeling. We have laser, shavers and Nair for hair removal why not focus on hair regrowth? It’s so weird and frustrating that this company is not putting aga first when they might have a good treatment for it.

      I’m waiting to hear about Samumed phase 2b results.

  20. Hmm. Follica is not so good. 100 hairs per square cm but Only 25 of them are terminal. 75 are neogenic. What is neogenic hair? It’s stemyoxidine on google.

    That would mean if u were slick bald you would only get thin hair back…. 2.5 cent = 1 inch. That’s means about 60 hairs per square inch.

    Here’s 45

    1. If someone can tell us what neogenic hair is that would be nice.

      What if u did a full transplant and revived all the hairs on the back of the head?

  21. I would imagine Follica isn’t showing before and after results because they have thin results that work but just not exciting

    1. This is the density we all desire:

      I think only a dense packing HT will achieve this:

      I wonder whether any of the upcoming non-HT techniques will ever be able to meet up to this needed/desired density.

      Spencer Stevenson is positive about soon-to-be released products:

  22. Egghead follica is not a cure, it’s a treatment that will work better that fin and minox. It will be a cure for NW1-3 if they respond to the treatment well. It will be a good treatment for NW4-5 but with HT combined. For NW6-7 well hair multiplication will be the answer

  23. Im wondering if cots knew that the dermatologist was going to post a pic of his device box? Or if he did that without permission just to start the advertisi advertising process so he can cash in. Think about it, if he is the first derm to offer it or advertise he will draw a lot of attention to his business which could help his practice in general.

  24. Hi guys!

    Finally i decided to go for a good HT here in Spain, im not gonna say the name cause i dont wanna make publicity here,
    but the thing is i have to wait for a year because he is bussy like the most,
    Should i start on minoxidil? i already taking finasteride (but i wanna change to dut)
    What you guys would recomend me?

    i’d been waiting for a new treatment ( Histogen, Replicel, brotzu and many mores ) but im sick of waiting and im turning 27 this summer and im NW2-3.
    My father is like me since he was 23-24 (so im probaly not gonna loose too much hair for the next years and a HT is a really good option for me)
    So should i start minox or should i wait after the HT?

    Thanks in advance guys


    1. Hi Cris,

      I never knew that most of them have a waiting list of 1 year! Probably you have chosen a good one because you have to wait 12 months.

      Anyway I think it is a good decision, because I am considering a HT as well and that is especially because I am sick of waiting (almost 35 years old). By the time something succesful comes out, there will be a waiting list as well because everybody wants it!

      Whether it’s necessary for you to use MIN prior to the procedure … I think nobody really knows the answer. I hope you will maintain on FIN, it’s a drug I can’t use unfortunately.
      That probably would have saved a lot of my crown.

      Good luck man. For example, I have seen a lot of Injerto Capilar videos. I am impressed by their results, even if they only show the best ones. If I spoke Spanish maybe I would travel to them.

      In the upcoming months I will start focussing on the North-West European HT market. Did you use a certain checklist with questions / actions you have to take during the HT intakes?

  25. Hi Netshed!

    Thanks for your words, to be honest i didnt make a checklist whith questions, i just spent a lot of hours looking on internet about all the new companies that never bring a new treatment to the market (at the moment) and cause i get tired of it, it’s almost two or three years ago when i start to get information about the HT, i visited a lot of pages and forums here in Spain, and i saw in 95% of the websites people talking about two greats HT surgeons here in Spain, one is Juan Couto ( it’s impossible to notice a HT if its done by him) and the other one is Rafael Freitas (Brazilian HT Surgeon living in Spain) the same as Couto, to be honest maybe you guys think that im doing publicity for them, but i dont care what you guys think,
    i just call two days ago ( because i still dont have my assessment ) and still have two wait one month and a half to have it, and from that moment, one year in a waiting list… that’s the only sh*t on here… but we have a saying here ‘ the good things make you wait ‘ or something like that haha, so im gonna wait for sure.
    i went to other doctor here in Spain, but he didnt give me much confidence, to be honest and after 10 days he call me like 5 times to see if i decided to go for a HT with him and i thought ‘ if you are a really good doctor you are not going to call every single person that got doubts for a HT ‘.. so i discard his option.
    and here i am, waiting for a HT and then wait without worries for a new treatment, i think that’s the only way to doesnt get crazy with this fu**ing problem, cause im all the time avoiding to go to the beach (living in the south of Spain..) … so, that’s it haha
    Just take a look of them on youtube

    1. Hi Cris,

      I think anyone will be in good hands with Rafael Freitas. I have seen many HT results of him. I googled Juan Couto now, and it seems that he is also a top HT surgeon.

      Good luck! And maybe share your results with Admin later?!

  26. Hi Admin,

    As you imply, this study about the dormancy of follicles and their re-activation after treatments has limitations and needs better research to back it up.

    But for what it’s worth, this idea of kenogen-reawakening is the theory behind stemoxydine (neogenic). According to company-sponsored investigation, stemoxydine “acts as a hair kenogen phase shortener, leading to an increase in visible scalp hair density.”

    The idea is that stemoxydine creates a hypoxic environment which promotes stem cell functioning and the re-awakening of dormant follicles from the kenogen phase to anagen. “Hypoxia signaling is mediated by HIF1, a subunit of which is degraded in an oxygen-dependent manner through prolyl-4-hydroxylase (P4H)-mediated hydroxylation”. Stemoxydine is a P4H competitive inhibitor and thereby helps create this hypoxic environment and promote hair growth.
    (quotes are from the L’Oreal research pieces at:

    Stemoxydine is talked about on forums for this hypoxic effect. For example, Swisstemple incorporates it in the belief that it will stimluate progenitor cells.

    Interestingly, the L’Oreal investigators very specifically state that stemoxydine only “revives” dormant follicles from ketogen. They feel that follicles which have not grown in a long time have no functioning stem cells, are not in ketogen, and cannot be revived.

    This research is all from several years ago; I haven’t seen any updates, so it would be interesting to see what their view is now about long-dead follicles.

    Best regards,


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