research Finasteride Use in the Male Infertility Population: Effects on Semen and Hormone Parameters 54 citations, September 2013 in “Fertility and Sterility” Finasteride can reduce fertility in some men, but stopping it increases sperm count.
research Negative Impact of Testosterone Deficiency and 5α-Reductase Inhibitors Therapy on Metabolic and Sexual Function in Men 31 citations, January 2017 in “Advances in Experimental Medicine and Biology” Low testosterone and 5α-reductase inhibitors can harm men's metabolic and sexual health; testosterone therapy may help, but discussing 5α-RIs' side effects is important.