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Jessica Joseph, RN, BSN, MHA
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Testosterone Therapy's Impact on Male Fertility

Jessica Joseph, RN, BSN, MHA
April 21, 2023
Young man sitting outdoors contemplating testosterone use
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Testosterone is vital to male physiology and responsible for healthy bones, muscles, energy, and sex drive. According to Urology Times, twenty percent of males in their prime reproductive years (ages 15-39) have issues with testosterone levels.   Underlying causes that contribute to this include:


  • Side effects from medications

  • Being overweight

  • Chronic conditions (kidney, lung, and autoimmune disease)

  • Injury to testicles

  • Endocrine issues (problems with areas in the brain that control hormone production)

  • Infections


Guided Fertility™ interviewed Mary K. Samplaski, MD, FACS, for her professional standpoints on synthetic testosterone use and its impact on male fertility.  Dr. Samplaski is board certified in Urology (residency training at Cleveland Clinic) and fellowship trained in Male Reproductive Medicine and Andrology.


Why do men seek testosterone replacement therapy (TRT)?


Most men make testosterone naturally in their bodies, barring any underlying medical issues. However, some men have low testosterone levels, commonly called Low T, that can impact their quality of life and have other health effects.  Low T can contribute to impaired libedo, erectile dysfunction, depression/anxiety, and lack of energy.  Taking testosterone can tackle some of these problems.  Studies are underway for testosterone use as a contraceptive, but this is not approved for use in the US or abroad. Some men think that “more is better” and may abuse testosterone therapy to gain more muscle mass. With the growing acceptance of online medical clinics and men’s health clinics, testosterone may be easier to obtain.


How does TRT affect sperm production?


Two of the most widely viewed misconceptions I have heard from my patients are:


  1. The answer to treating low sperm counts is to take testosterone

  2. Low testosterone levels are always correlated with low sperm production


Taking testosterone synthetically will lower the testicles own sperm production, therefore lowering sperm counts as a side effect.  It suppresses two vital hormones that are responsible for sperm production. The first is follicle-stimulating hormone (FSH), which is responsible for producing sperm in the testes, and the second is luteinizing hormone (LH), which is responsible for producing testosterone in the testes. 


Furthermore, not all men with low T will have low sperm counts, or vice versa. This is because when men are tested for testosterone, it indicates levels in the blood, not in the testes.  So, men who have low serum (blood) testosterone levels can theoretically still have higher testosterone levels in the testes, which does correlate with sperm production.


What are the long-lasting effects of TRT?


When men stop using TRT, sperm parameters may return to normal.  However, it can take months to years for the parameters to return to normal, which result in a delay in conception.  Rarely, some men, after taking testosterone, may never regain normal sperm counts.  These men may need fertility treatments or donor sperm to achieve parenthood with their partners. Therefore, it is typically advisable that men avoid taking synthetic testosterone until after having children, or be aware that there is the risk that their sperm counts may not recover after cessation. 


Are there alternative methods to boost testosterone production without affecting sperm quantity?

Depending on the cause of low testosterone, alternative methods for treating low testosterone can be medications such as clomiphene citrate, letrozole, and GnRH agonists, which are injectable hormones.  These medications increase FSH and LH, the signals to the testicle to increase T and sperm production. Addressing underlying medical conditions that can be the root cause of low testosterone should also help.  Following a proper diet, getting enough sleep, and exercising can also positively impact testosterone levels.

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