Information needed on DHT blood test levels

[Hair87]

Friends,
I recently got my DHT levels tested after being on finasteride for 4.5 months (Generic fin by Dr. Reddys).
5-Alpha-DHT Serum: 709.71 pg/mL (Ref Range: 250-990)

I feel the levels are still very high despite taking finasteride. And I feel this is the reason it is not working for me.

Can anyone guide as to what should be ideal DHT levels on finasteride? How long after being the drug, we should get the DHT levels tested?

I normally take finasteride at night after dinner. I got the test done in morning after 10 hour fasting.