Testosterone (T) is the major male hormone and plays a large role in establishing sex drive, supporting sexual function, maintaining muscle mass, and sustaining energy levels. A certain baseline amount of naturally-produced T is also necessary for normal sperm production. Many men deficient in testosterone take prescribed T as medication to normalize their levels and restore their energy and sex drives. Other men abuse T or related hormones as anabolic steroids to enhance their response to weightlifting. When T is given as a medication or abused by bodybuilders, it has the counterintuitive effect of driving down sperm production. In fact, testosterone has been extensively investigated as birth control for men and often results in sperm counts plummeting to zero.
Why does this happen? When you take testosterone or other androgenic steroids, your body recognizes that it does not need to produce its own testosterone. Your testicles shut down, which means they stop doing the two things they do - producing testosterone and producing sperm. The impact of T medication on sperm production is not permanent but can last for many months. There are options for men with low T to treat their condition without negatively impacting sperm production.
Men who are taking testosterone and want to conceive should consult a urologist who specializes in male fertility, ideally at least 6-12 months prior to the time that pregnancy is desired. Often medications can be used to speed up the recovery of sperm production.
