Why Doesn’t Propecia Work For Everyone if It Blocks DHT?

If propecia blocks DHT and DHT causes hair loss, why doesn’t this drug work for everyone who takes it?

The genetic elements of the balding genes influence the degree to which finasteride works. I would imagine that taking the new HairDX (RxR) Genetic Test for Finasteride might shed some light on who finasteride might work for best. Although it is a press release, this link contains a lot of good info about why Propecia works better for some — check it out here.