If Dutasteride almost completely shut down DHT in the body, why does it not work for my hairloss?

I've been on dutasteride for over 6 months without any success whatsoever. Prior to that I was on finasteride for 1.5 years without results. If DHT is the main cause of male pattern baldness, and Dutasteride lowers dht to almost non existing why does my hairloss not stop or even slow down??