Finasteride works by inhibiting the type II 5α-reductase enzyme.
This enzyme is responsible for converting testosterone into dihydrotestosterone (DHT), a potent androgen significantly impacting prostate growth and hair follicle miniaturization.
- By blocking 5α-reductase, finasteride directly reduces the conversion of testosterone to DHT. This reduction in DHT levels leads to a decrease in prostate size and may improve hair growth.
The degree of DHT reduction varies individually, but studies consistently show significant decreases.
Studies show finasteride typically reduces DHT levels by 70% or more. This reduction is primarily observed in serum and prostatic DHT levels.
It’s important to understand that finasteride doesn’t affect all forms of 5α-reductase. It mainly targets the type II isoenzyme, which is predominantly found in the prostate and scalp.
Therefore, finasteride’s impact on DHT levels is targeted, primarily affecting areas where the type II 5α-reductase enzyme is prevalent.
