According to a recent article in Translational Andrology and Urology, there has been a 170% increase in testosterone prescriptions over the past five years¹. Testosterone can be prescribed to increase low libido, assist with fatigue², or used by the image-conscious as a way to increase muscle mass. However, there is a downside for those men who are wanting to father more children. Taking an external (exogenous) form of testosterone, whether it be by injection, patch or tablet – has shown to have a dramatic impact upon sperm production^1,2,3,4.

The article in Translational Andrology and Urology explains that the external form of testosterone causes a negative feedback loop on the body’s natural hormone production, resulting in a decrease in overall testosterone levels in the testes¹. This reduction causes the degeneration of the germinal epithelium (see Fig 1)⁵, which contains the developing sperm cells. It can suppress natural testosterone to such a degree that sperm production is dramatically reduced, resulting in low sperm concentration (oligozoospermia) or even complete absence of sperm in semen (azoospermia) within 10 weeks³.

Figure 1: Germinal Epithelium with cross section of developing sperm.

All hope is not lost however, as studies have shown that sperm production can return once a man stops taking external testosterone^2,3. The general consensus is that taking the hormone supplement does not have a permanent impact on fertility. There have been many studies carried out on the extent of recovery of a male’s sperm production after ceasing external testosterone¹. They give optimistic results, with all men returning to their individual baseline value within 12 months, however some men took as long as 24 months to regain pre-treatment sperm production levels.

It is advised by Dr. Bradley Anawalt, a prominent endocrinologist and chief of medicine services at the University of Washington Medical Centre that, “men should avoid testosterone supplements until they are done having their own biological children.²” In the very least, male patients should notify their fertility specialist of any medications or supplements they are currently or recently have taken, as this can help shed light on possible reasons for a couples’ infertility.

For additional information about the effects of testosterone supplements on sperm production, please call our office on (07) 5478 2482.

Sources

¹ Crosnoe, L.E., Grober, E., Ohl, D., Kim, E.D. (2013). External testosterone: a preventable cause of male infertility. Translational Andrology and Urology, 2, 106-113. doi: 10.3978/j.issn.2223-4683.2013.06.01
² Dotinga, R. (2014) Testosterone Supplements Maybe Hurt Male Fertility, Study Finds. Retrieved from https://healthyliving.msn.com/pregnancy-parenting/advice/testosterone-supplements-may-hurt-male-fertility-study-finds
³ Schieszer, J. (2010). Injectable Testosterone Preferable to Gel. Renal & Urology News, 9 (1),
⁴ Testosterone therapy: A misguided approach to erectile dysfunction (ED). (2012, Jun 19). PR Newswire. Retrieved from https://search.proquest.com/docview/1020956980?accountid=13380
⁵ Université catholique de Louvain. (2005) Genetics and Gametogenesis. Retrieved from https://www.md.ucl.ac.be/didac/anat110/Genetique%20&%20gametogenese_files/image023.jpg