When Avodart came on the market, there was an assumption and a smidgeon of industry sponsored data to suggest that it would out perform Propecia in regards to its hair growth benefits. It seemed all too obvious, being that Avodart is a dual 5 alpha reductase inhibitor and Propecia/Proscar is a single 5 alpha reductase inhibitor.
This assumption has been only partially correct. The feedback we’ve gotten over the last few years since Avodart came out has been anything but uniformly positive. Some have significantly improved their hair growth while at least as many others have gotten substantially worse, enduring increased shedding and rapidly receding hairlines. So common is this apparent occurence that the “Avodart shed” actually became a term coined in newsgroups.
The following study appears to shed some light on this phenomena. In a nutshell it suggests that you may have an either positive or negative response to Propecia or Avodart depending on your genotype.
Our advice:If you decide to use either Propecia or Avodart, self monitor for increased (not daily incidental) shedding, and give it at least 3-6 months. If you continue to show signs of accelerated hair loss switch to the other compound for an equal amount of time. Remember, we are talking about accelerated hair loss, not “little to no results” because even the best anti-androgens are very slow acting and often stabilize further loss without any cosmetically significant regrowth.