Inhibition of Steroid 5 Alpha-Reductase with Finasteride: Sleep-Related Erections, Potency, and Libido in Healthy Men

The study investigated the effects of finasteride, a 5 alpha-reductase inhibitor, on sleep-related erections, potency, and libido in healthy men. The results showed that finasteride did not significantly affect erectile function, but self-reported decreased libido was more common in men treated with finasteride than in placebo-treated control subjects. The study suggests that DHT may be involved in central nervous system processes underlying human sexual function, but objective physiological measures indexing finasteride-related changes in erectile capacity are not available. Overall, the study supports the feasibility of using a type 2 inhibitor to treat benign prostatic hyperplasia without impairing erectile function.