Several doctors told me by that taking Finasteride (AKA Proscar or Propecia), I have a better-than-even chance of reducing hair loss.
This Wikipedia article cites one study the corroborates this claim, but it leaves some important questions unanswered. For example: Was the study conducted by someone affiliated with a pharmaceutical company? Is it possible that other studies, that had different conclusions, have been conducted but not published?
Can anyone cite more reliable information about this issue?