Yeah an interesting comment on the bottom of that page about how that guy was actually not bald on a different picture shortly before he died, and that picture might have been edited or changed. Also interesting how this comment says this eunuch had a mature hairline even with nearly all his testosterone removed but still had 30% of his baseline DHT.
I think though men have other forms of androgens other then just testosterone and DHT so maybe removing all of them and increasing estrogen is what you need much like women have to not lose any hair.
"The last Eunuch in China did not go bald. This falsehood is being propagated on hair loss forums, mostly by people who have their own alternate theories for the etiology of Androgenetic Alopecia, and is based on a bad, overexposed, and maybe doctored picture on the cover of a book they’ve never read.
Look him up. There is one picture of him shortly before his death with the man who wrote his biography, and he has a full head of thick, but shortly cropped (which is why he looks bald) white hair.
Interestingly, however, he did develop a mature hair line, and since a castrate will have 30% of his baseline DHT and only 5% of his baseline T, this basically excludes T as the cause of at least his mature hair line…
… and probably everyone eles."