Well here is my explanation of why average haircounts drop after the first year on Propecia. It's important to note that these are average haircounts and therefor say nothing about individual response. First you must think about what makes the average haircount in a group go up or down, ie:
- people who gain hair increase haircounts.
- patients who maintain hair have no influence on haircounts.
- patients who lose hair decrease decrease haircounts
It follows from this that average haircounts increase when hairgain in the group is higher than hairloss. Average haircounts decrease when hairloss in the group is greater than hairgain. In the case of Finasteride we can say that hairgain was greater than hairloss in the first year, and smaller thereafter.
You have, for example, a hypothetical drug that gives 9 in 10 guys all their back in 12 months and after those 12 months they keep (or maintain in our hairloss jargon) that full head of hair for life. But in 1 guy it does nothing. In this case average haircounts will shoot up in the first year, because hairgain from those nine guys is much greater than the hairloss of the other 1. But once they have their full head of hair, there is no more hairgain. At this point the 1 non-responder will start to drag the average haircount down again.
Basically I'm saying that unless you have a product that minimally maintains hair for 100% of it's users, there will always be a time when hairloss outweighs hairgain and thus average haircounts decrease. I'm not saying Propecia works forever, but you can't tell from those trial results that it's effectiveness decreases either. The only way to find out is to take the drug and see how it works for you.
And oh yes, I believe the use of hairloss treatments will become more common in the future, as those treatments become more effective and widely known.