TLDR Finasteride effectively treats hair loss and prostate issues with minimal side effects.
The review discussed finasteride, a 5-alpha reductase inhibitor, primarily used to treat benign prostatic hyperplasia (BPH) and male androgenetic alopecia. It highlighted that finasteride works by blocking the conversion of testosterone to dihydrotestosterone (DHT), which is responsible for male pattern hair loss. While there were concerns about potential male sexual dysfunction due to its effects on testosterone and DHT, some studies reported insignificant or acceptable adverse effects that diminished over time, suggesting that discontinuation of finasteride was often unnecessary.
January 2013 in “e-Jurnal Medika Udayana” 
2 citations,
January 2010 in “Hormone Molecular Biology and Clinical Investigation” Low dose finasteride decreases certain steroids, possibly increasing depression risk.
9 citations,
January 2009 in “PubMed” Finasteride treatment can decrease certain steroids and increase others, possibly leading to depression symptoms in some cases.
408 citations,
May 2004 in “The Journal of clinical endocrinology and metabolism/Journal of clinical endocrinology & metabolism” Dutasteride more effectively lowers DHT levels in men with enlarged prostates than finasteride.
June 2001 in “International Journal of Cosmetic Surgery and Aesthetic Dermatology” Finasteride improves hair growth in men with androgenetic alopecia.
3 citations,
June 1996 in “PubMed” 
93 citations,
January 1996 in “Clinical Pharmacokinectics” Finasteride helps regrow hair and shrink prostate by reducing DHT, with some sexual side effects.
73 citations,
January 1994 in “European Urology” Finasteride works better than Permixon in reducing dihydrotestosterone levels.
124 citations,
January 1993 in “The Prostate” Finasteride effectively inhibits 5α reductase, while plant extracts like Permixon and Bazoton don't show significant results.
12 citations,
January 1993 in “PubMed”
