Is the Mechanism of Finasteride Understood?

Dr. Rassman,
Out of curiosity, is the actual biochemical mechanism of finesteride well understood? If the mechanism is enzyme inhibition and the drug is present in excess in the body, why would it not completely stop hair loss? Does the drug lose effectiveness because there is too much DHT in the system to inhibit or is there some secondary or tertiary contribution to hair loss beyond DHT?

(I guess I’m asking for your general thoughts because I’ve been reading the literature and haven’t found much)

A sincere thanks for your time and expertise.

The drug competes with DHT in a competitive process and it seems to win out about 70-80% of the time. That is why I believe it does not block the entire receptor site. That is a technical answer. With regard to other agents causing hair loss, I am sure you are right in your suspicions.