INT said:Thanks for the tip but what about the point I made in my post before yours?
The sooner you start, the more hair you will end up with in the long-run. You wouldn't be "wasting" the years that finasteride remains effective.
Here's a hypothetical situation...
Let's say that you were destined to start losing hair this week. If you are an excellent responder to finasteride, you probably wouldn't see any hair-loss for 2-3 years if you started right away. After that, the loss would occur at a much slower rate than without the drug.
It's always better to start earlier because finasteride (or any other treatment) won't grow back all the hair you lost, but it can keep it from falling out in the first place.