We don’t know the pathophysiology of PFS. Dr. Rassman posts on a Reddit about PFS or hair loss. I find that he is sympathetic to the reality of PFS, but seems to talk about unknown areas as if he has the answers. He doesn’t have the answer, and no doctor has the answer.
It’s also concerning that he quotes an explanation from HairLossHelp (which now redirects back to Rassman’s site), and this does not appear to be a real medical term. It is vague. Maybe it means “immediately increased sensitivity to androgens.” But then what? It’s just a multi-syllabic term that is not really describing or explaining anything new.
There has been plenty of talk here, and some in the research literature, about dysregulation of androgen receptors (maybe upregulation, maybe downregulation). But that’s just a suggestion of where to look, not a description of what’s happening.
If you want to know the state of the science, I would stick to PubMed.gov. If you search “reflex hyperandrogenicity” on pubmed, none of the three results use this term, and none are relevant. So this is apparently a made-up term that has no use for PFS patients.
There is also a bibliography of published research on adverse effects of finasteride here: https://finasteride.network