The 5-α-reductase inhibitors finasteride and dutasteride are frequently used in the treatment of androgenetic alopecia and benign prostatichyperplasia. These drugs are effective at reducing levels of dihydrotestosterone, the primary androgen responsible for the pathogenesis of both these conditions. However, finasteride and dutasteride have also been shown to produce an increase in the incidence of sexual dysfunction, namely, impotence, decreased libido, and ejaculation disorder. The purpose of this study is to review the existing medical literature with regard to the sexual side effects of 5-α-reductase inhibitor therapy. This review is an extensive look at the sexual effects of 5-α-reductase inhibitors and compares outcomes for finasteride versus dutasteride in addition to comparing sexualside effects for each of the different dosages prescribed of finasteride and dutasteride.