Occasionally a reader of The Niche will ask me about stem cell therapy for hair loss. I’m interested in this research because I’m fascinated by stem cells. Admittedly I don’t have as much hair as I used to so that’s sometimes on my mind too.
So where do things stand?
There is some reason for more long-term optimism on stem cells for baldness late in 2021, but you’ve also got to beware of scam offerings of clinics & sketchy online products.There’s too much hype out there in general these days.
The goal of today’s post is to educate and fact-check. I’ve also pasted a video I did on this topic below if you want to watch an overview of the post.
What’s in this post
What causes hair loss?
There are a variety of causes of hair loss. In men the most common etiology of baldness is hormonal. This is the same as so-called male-pattern baldness, which is in part related to increased levels of dihydrotestosterone or DHT. The drug finasteride works by interfering with DHT. Androgens also can cause the hair loss that some women experience.
Often the term hair loss is a misnomer. In many cases the hair isn’t gone but has shrunk so much due to DHT that it is microscopic. In a way this is good news because what is not gone in theory could be restored by stimulating growth.
There are many other less common causes of hair loss in men. For both men and women as well as children hair loss can also be caused by burns or other injuries. Some autoimmune disorders can also cause hair loss if the immune system attacks the hair follicle.
Note that the hair has to have a healthy follicle to grow. DHT acts negatively on the hair follicle.
A new piece by Gina Kolata in the NY Times Losing Your Hair? You Might Blame the Great Stem Cell Escape explores the link between stem cells and hair loss. It kind of goes both ways. Stem cells play an integral role in hair follicle function and dysfunction there may contribute to baldness. Here’s the original research article in Nature Aging that Kolata wrote about in the new Times piece. Interestingly, they report that stem cells in a sense “escape” the hair follicle. Once gone or depleted in stem cells, the follicle ages or doesn’t function right. Individual hairs grow and regrow directly via skin stem cells in the follicle.
Prospects for future stem cell therapy for hair loss
If some stem cells leave the proper follicle area, what about a new approach using stem cells?
Let’s start with the encouraging part of this story. The sheer amount of ongoing research on stem cells for baldness is reason for hope.
Many research labs including biotechs are working on stem cells for hair loss. Some of these teams have produced data that provide real hope on this front.
As I discuss more below, there are many papers to read and clinical trials going on in this space too.
Ultimately, I think this is going to work in one way or another in the coming decades or so.
How might stem cells for baldness potentially work?
There are several possible cell therapy approaches to baldness. I’m going to discuss the 3 main ideas, starting with two transplant kind of angles.
Stem cell transplant.
In one approach, new skin stem cells would be injected into the scalp or any other balding area. They would grow new follicles that in turn would grow new, healthy hairs. A lot is known about those particular dermal stem cells. This means that in theory we could grow new hair in bald people if we could reproducibly produce enough of those “hair stem cells” for lack of a better term to address large areas of baldness. Regeneration of follicles is being intensively studied as you can see in the image above. Some of this work in mice is likely to lead to more clinical trials in people.
Ideally you’d want these new follicles and their associated populations of stem cells to stick around for many years or even decades. One challenge is that the recipient of the new hair via the cells is likely still making excess DHT, which may just inhibit the new hairs the way it did the old ones. It’s not clear if somehow the cells could be engineered or tailored in some other way to be DHT resistant.
Transplant of lab-grown hair made from stem cells.
Another idea is to transplant actual hairs grown in the lab rather than hair stem cells. In this way you could grow tens of thousands of hairs in a bioengineering lab from stem cells, ideally the patient’s own stem cells, and then transplant those into their bald region en masse.
It’s unclear whether this approach or the stem cell transplantation idea would be more practical. On the one hand if you transplant stem cells into a region like the scalp you cannot be sure they’ll make hairs so that could give the lab-grown hair idea a better shot. However, with the stem cell transplant idea you could easily transplant hundreds of thousands or millions of cells or clusters of cells at once so even if only a fraction made hair you might get robust overall hair growth.
Stem cell-based drug approach
A stem cell-related drug approach. Finally, stem cell research could yield a drug that reawakens dormant follicle stem cells in the skin to go into a more active hair growth phase.
This research could include drug screening on stem cells in skin or hair models in the lab to find new compounds that have the desired effect without major side effects.
What do the scientific literature and data say?
I checked out Clinicaltrials.gov to see the state of the literature. I did several searches using ‘hair loss” and “baldness” as terms, which yielded similar results. There are 15 such trials listed there in 2021 as compared to my records of only 10 trials in 2017, which is a decent increase. Not all of the trials are interventional ones but a few are. Still, I’m surprised there aren’t more active interventional trials. I’ve included a map of the trials above.
Bonafide clinical trials take time to try to prove something is safe and effective. Many also don’t succeed.
What about published data?
There are hundreds of articles on stem cells and hair on Pubmed, not all of them of course relevant to human hair or baldness, but still it’s a very active area of research. The number of articles is consistently growing (see graph above from PubMed) so that’s encouraging.
Of course, there are existing drug-based approaches to baldness like Propecia (finasteride) and minoxidil, but they are expensive, can have side effects, don’t always work, and must be taken forever.
There are also totally bogus things out there for baldness including some that are painful or risky. Here is my (non-medical) advice. Save your money for when real, proven stem cell therapies for baldness arrive that are safe and effective. Hopefully, that’s not 20 years away. Don’t go to stem cell clinics for hair loss.
- PubMed search on October 13, 2021 for stem cells and hair
- Clinicaltrials.gov search on October 13, 2021 found 15 relevant trials.
- American Family Physician: “Alopecia in Women“
- Finasteride: a review of its use in male pattern hair loss, journal Drugs
- What You Need to Know About DHT and Hair Loss, Healthline