Dutasteride is better than finasteride as reported by user below (from Reddit)

One point that I think is worth mentioning is that the deviation in response for Dut is much narrower than it is for fin. Finasteride inhibits 70% +- 18% of Dht while Dut is 94% +- 3%. As you can see, it’s clear why there are about 14% non responders to fin when they may only be inhibiting 52% DHT. With Dut, everyone in the study was above 90% inhibition so you’d have to be terribly unlucky to not respond.

For those who are thinning on Fin or who want better results, Dut is all but guaranteed to work better than fin. Dut is three times as potent at inhibiting 5AR2 which is what we want to inhibit. As a downside, Dut also inhibits 50% of 5ar1 which has unknown consequences.

I keep reminding Reddit readers that dutasteride is reported to cause sterility in a small number of men who take it as possibly is finasteride as well although the FDA trials, which are not present with Dutasteride, is available for finasteride. Neither of these medications have long term studies on young men under 30 years old.  I generally tell patients that it is best to stay with drugs that have an FDA clearance for hair loss use as finasteride is than drugs that don’t (dutasteride).