I'm no expert and I'm new to the forums and have only been researching for a couple of months. I am not pretending to understand all of the factors that lead to hair loss but I now know enough to be clear that the collective evidence around why we lose our hair still has a lot of unknowns and conjecture around it. And while our genetics is clearly part of the story, and DHT and enzyme reaction is part of the story, that's not answering all the questions.
I've read and collected some interesting observations that point at MPB being more complicated than the prevailing theory.
Firstly, inflammation, fibrosis and calcification and tighter skin across the scalp are associated with scalps that are experiencing male pattern baldness.
So consider why minoxidil helps hairs grow back. There isn't a conclusive answer why but one strong possibility is that it helps with blood flow to the hair follicles because it’s a topical vasodilator (it improves blood ﬂow). This improves the oxygen and nutrient supply to our hairs. What's clear though is minoxidil doesn't have anything to do with the genes, DHT action that finasteride does.
Why does running dermarollers and microneedles across the scalp lead to hair regrowth? It can't possibly be affecting the DHT / 5 alpha reductaze enzymes. Why does PRP seem to cause hair regrowth when done "properly"?
A study of patients who had botox injected into the muscles around the back and sides of their skulls showed significant hair regrowth. The botox "deadened" those muscles for months at a time which led to the skin at the top of the scalp being left looser because the muscles weren't flexing and causing the scalp to be pulled tighter.
Note that the hairs that fall out and the follicles that stop working are all on the galea membrane that runs on the top of the skull. Conversely the hairs that overlay the muscles surrounding the scalp are in the donor areas and they don't fall out. Note the image that I pasted from the book called "Perfect Hair Health" by Robert English that shows how the areas of scalps that have the most tension are the areas where the hair tends to recede first.
So tension and skin laxity seem to be a factor and they're associated with inflammation and calcification around the follicles, which can restrict blood flow to the follicle, and may signal DHT and 5 alpha reductaze to bind to the follicle to deal with the inflammation which area. Note that DHT is anti-inflammatory and it alone doesn't cause follicles to stop working, in fact serum DHT elsewhere in our body promotes hair growth.
So why does donor dominance work so well? Why do the hairs transplanted from the donor area take hold in slick bald areas or survive long after the native hairs fall out?
* Possibly because the follicles come across with healthy tissue that hasn't been affected by the years of tension, inflammation and calcification that exists in the recipient area.
* It's possible that the newly transplanted follicle and tissue actually signals for surrounding tissue to regenerate
* Even donor grafts can thin and follicles can die over time
Read here for more explanation: