Escuse me Dean, but I've been on almost all those things since 1990, and there is no such things being said by EVERYONE. although I'm sure a some say that.
Avodart (Dutasteride) works like finesteride which has been proven countless times to WORK on DHT driven hair loss (which is what most men have).
If you have some other type of hair loss it won't work. Only a trip to the hair specialist can tell you that.
If it is a very very aggressive DHT driven loss (totally bald before 30 if you don't do anything for example), you may not get a full response (but you will get something).
Since spiro works on hair loss by simply blocking T's effect on the hair shaft and diminishing overall T production, how on earth could it promote hair loss!! T at the hair folicle is the main reason for hair loss, how could it promote it? What means of action this molecule could use to do that!
A medication cannot promote something outside the realm of its biological action.
Also, I don't care how many people say it on one particular board (which is kind of a self-selected survey with huge bias), that's not how you prove a medication has a certain effect or not. Anedoctes prove nothing.
If you take spiro or dutasteride or finesteride, without estrogen, the quicker cycle the hair will be in, will initially push many towards dormancy (shedding). Coupled with estrogen there would be less of that since estrogen increases the time when the hair is growing and not dormant.