Is It True That Transplanted Hairs Never Thin?
Contrary to popular belief –
healthy hair follicles transplanted into thinning or balding regions can eventually thin too.
This is known as “Donor Dominance” – the observation that transplanted hairs eventually take on the look of the hairs near which they’re transplanted. If those hairs happen to be thinning, your transplanted hairs will likely also miniaturize (albeit at a slower pace).
This is contrary to what most people read online and what most surgeons say. Typically you’ll hear that hairs transplanted from the back of the head are “
immune” from androgenic alopecia and never miniaturize.
Then Why Do People Say That Transplanted Hairs Never Thin?
This assumption – that transplanted hairs never thin – arose from the
first few decades of hair transplantation research.
Over fifty years ago, researchers published a study highlighting an attempted hair transplant. Scientists took thick healthy hairs from non-bald regions in the back of the scalp and transplanted them to balding regions. These hairs continued to grow normally for the duration of the study, and so scientists concluded that these hairs would continue to grow in perpetuity because they were protected, for reasons unknown, from male pattern baldness (male pattern baldness).
Following studies showed similar results. During each study’s duration, most hair follicles that survived transplantation tended not to miniaturize.
The key term here is study duration. The majority of these studies ranged from six months to three years. Is that long enough to gauge whether transplanted hair is thinning? Let’s look at our end points.
It takes infants over half a decade to grow hair. It takes adults multiple decades to lose hair. So a three year observation period probably isn’t long enough to say whether transplanted hairs are forever protected from male pattern baldness. In fact, basing my opinion off of anecdotes, I think the opposite is true – that transplanted hairs
do thin.
I’ve provided email and video support to dozens of hair transplant recipients. Of the ones who received a transplant five to ten years ago, nearly all of them claim most of their transplanted hairs have already fallen out. I also have a friend with a hair transplant who’s experiencing the same thing. That’s not very encouraging.
So the studies conflict with the anecdotes – or at least the anecdotes I’ve been told. My guess is that this discrepancy exists due to too-short study durations. But I’ve also read surgeons say this could be caused from
transplanting follicles from too close to the vertex – thereby transplanting hairs already susceptible to baldness.
Why Do Many Hair Transplant Recipients Report Their Transplanted Hairs Are Thinning Years After Surgery?
The reason why isn’t yet 100% clear. But based on the evidence, my theory is this:
Healthy donor hairs are transplanted into balding regions of the scalp. And if you’ve read other articles on this site, you know that balding scalp regions have
elevated tissue DHT, fibrosis, calcification, excess sebum/dandruff build-up, collagen remodeling, a fused galea, and a host of other symptoms stemming from chronic, localized inflammation.
These conditions starve the follicles of nutrients and proper blood flow. This results in follicle miniaturization, and over a series of hair cycles, baldness.
These scalp conditions tend to precede hair loss. They kick start the balding process. But the process in which hairs miniaturize still takes decades.
By that same logic, if you transplant thick healthy hair follicle units into balding regions, it might also take decades for those transplanted follicles to thin from reduced nutrient and blood supply. These hairs eventually miniaturize too, but since they’re starting out thick and healthy, it takes a long time.