First thanks to Hellouser for his efforts and hard work here.
I think the Histogen data is very interesting. They don't really pin down the precise action of the injected "cocktail", but i would point out something significant that can be seen in the close up pics on their website.
First i should explain the background to my own views for those who don't already know. I think hair loss research took a wrong turn many years ago, and this is the reason for the on-going delay in producing more effective treatments. My personal critique of historic hair research can be read here.
https://independent.academia.edu/StephenFoote/Papers
The simple fact is that hair loss research is all about finding the cause of restricted growth of the anagen follicle. Yet current hair growth research ignores the most basic tissue growth control of all in recognised Physiology. According to mainstream science this universal control has the final say on all normal tissue enlargement in-vivo, and so must also apply to hair follicle enlargement in-vivo.
This is described in my article linked above, and basically means to increase hair growth we need to shrink the tissue around the follicles. One clear sign of tissue shrinkage is a crazing or wrinkling of the skin. People are aware of this effect with Minoxidil.
The baseline and one year close up pictures on the histogen site, also clearly show this wrinkling of the skin in the after one year picture.
http://www.histogen.com/applications/hsc.htm
Best to copy save then enlarge to see in detail.
The other important thing about this universal growth control is that any attempts to get around it will fail, or be deemed to dangerous to be licensed. This spatial growth control prevents tissue growth from invading other tissues, and only cancer cells can get around this. There is some relaxation of this control in the healing process, and this is in line with the wounding effects being researched in hair growth.
But messing with the WNT's pathway and other strategies to get around this natural growth restriction, is asking for trouble and not necessary anyway.
With a little focused research on reducing the external conditions that restrict follicle growth, we could have more effective, cheaper, and safer treatments.