no conclusive evidence yet...there are some studies showing that it is a dht inhibitor...but regardless its no where near as effective as finasteride or dutasteride
Yep, I take it in addition to Saw Palmetto. B-Sitosterol is one of the active phytosterols in Saw Palmetto. I don't believe either of these inhibits 5AR but instead blocks the androgen receptor. There's very low amounts of B-Sitosterol in SP extract so combining both apparently helps the effects. B-Sit is very cheap too, much cheaper than SP extract though this has much more history of benefit for our cause that B.S. alone does.
You will found good info about this if you go to groups.google.com and search the alt.baldspot newsgroup.