TLDR Finasteride may cause infertility in rats by affecting epididymis and sperm function.
The use of finasteride, a 5 a-reductase inhibitor commonly used to treat male baldness, may lead to epididymal changes and infertility in rats, according to a study by Garcia et al. The study found that finasteride caused changes in the structure and function of the epididymis, as well as reduced sperm function and fertility potential without any significant alterations in sperm production. The authors postulated that the poorer sperm parameters and fertility potential in those rats treated with finasteride were due in part to the rapid transit through the epididymis. The study adds experimental weight to the limited literature suggesting that the use of finasteride could result in male infertility.
20 citations,
April 2012 in “Fertility and Sterility” Finasteride causes lasting fertility decrease in rats.
36 citations,
February 2011 in “Fertility and Sterility” Finasteride use may cause sperm damage and infertility, stopping it can improve sperm health.
100 citations,
April 2010 in “Expert Opinion on Pharmacotherapy” Hair loss in men treated best with early medication or transplant, new treatments researched.
34 citations,
January 2004 in “Revista do Hospital das Clínicas” Finasteride may worsen infertility in men with existing issues, but stopping it can improve sperm health.
104 citations,
October 1999 in “The Journal of Urology” Finasteride doesn't harm male fertility or sperm quality, but may slightly reduce ejaculate volume.
77 citations,
June 2015 in “Nature Reviews Urology” Some common medications can harm male fertility, but many effects can be reversed.
20 citations,
April 2012 in “Fertility and Sterility” Finasteride causes lasting fertility decrease in rats.
November 2023 in “Brain Sciences” Some medications might contribute to male infertility, with finasteride showing a high number of reports.
1 citations,
January 2015 in “Journal of Clinical Toxicology” Babies were mostly born healthy from fathers who took finasteride, but some pregnancies ended early; more research is needed.
June 2021 in “Archives of Advances in Biosciences” Finasteride reduces sperm count and quality and alters hormone levels in mice.