Does Minox only work for approx 24 months?

[aceman]

I keep hearing that minox only work for a year or two before it stops working at all. If that is the case, then why do doctors always tell you to start treatment as early as possible? Strategically speaking, shouldn't you try to delay using it as late as you can, as long as you have follicles left? As in, you start minox only when your balding starts to get really bad, but before completely bald of course.

Is that a good strategy? Also, has anyone had good effects from minox only that lasted more than a couple years?