The RU58841 was from a French outfit originally. Supposedly the compound was merely an androgen receptor blocker that had three times the affinity for androgen receptors than DHT does. It can be purchased from a Chinese online pharmacy. Its very expensive and the batches they mix vary in effectivness if what the hairsite.com posters say is true. The mix that has an awful odor supposedly works better. The stuff is highly flamable, and does not have a long shelf life.
Will Brink, life extension writer, knew some bodybuilders (wealthy ones) who had some private formulations made for personal use (mucho expensive). According to these guys (veterans of Propecia, prox, etc.), it was the best stuff ever put on their heads as far as retaining hair. Problem is, even if you cut androgens with literal castration, youre still not going to "grow back" much of what was lost. Damage (proboably by the immune system) and skin changes around the follicle, have been done if the hair has been lost for a while.
Im still wishing someone could formulate a "all in one" topical to include an anti-androgen, copper peptide, SOD's and catalese (protect from oxidative damage), and a nitric oxide or plain ol' minoxidil all in one topical. Affordable too. Its too much of a pain in the *** to use two or three topicals a day.