Is Testosterone Replacement Therapy a Threat to Men’s Fertility? 

Men across the country are turning to testosterone replacement therapy to treat issues with sex drive, weight gain and fatigue. Many of these men have seen ads that portray the treatment as a fountain of youth one that will help them retain the vigor and fitness of their 20s. One side effect of artificially increasing testosterone can be a lowered sperm count, which is a direct cause of fertility issues. Many men are completely unaware of this potential side effect, and unfortunately doctors who are providing the treatments do not always inform the patient.

What Is Testosterone Replacement Therapy?

Testosterone is a hormone naturally produced in both men and women with men having higher amounts. As we get older, the levels of testosterone in our body naturally drop and doctors sometimes recommend hormone replacement therapy to reverse issues of fatigue and low sex drive. The treatment is commonly referred to as TRT. Many men report great results with TRT, and they find that they have increased focus and drive, that they no longer have difficulty building muscle mass and that their libido is increased. For these men, the treatment can be considered a success.

What Are the Effects on Fertility?

Like all medical treatments, hormone replacement therapy can cause some side effects. In the case of TRT, those side effects can be related to blood clots, increased breast tissue and lower sperm count in men. Clinical trials have shown a correlation between using testosterone replacement therapy and reduced sperm counts. This means that men who have not yet had all their biological children should be wary of using TRT. Unfortunately, many doctors who prescribe the treatment are not really focused on issues of fertility or family planning, and they may fail to warn patients that the supplement has been linked to fertility issues. Other men are relying on over-the-counter types of testosterone supplements and may not really consult with a medical professional at all.

It seems counterintuitive that taking using testosterone replacement therapy would negatively affect fertility. After all, it is meant to increase libido and sex drive. It turns out that although men do need correct levels of testosterone to produce healthy and viable sperm, testosterone must be produced by the testes themselves to have the right effect on sperm count.

GnRH Crucial

The human body uses complicated feedback loops to determine hormone production and regulate sex organs. In the case of sperm production, we are specifically looking at the feedback loop of a hormone called gonadotropin-releasing hormone, or GnRH.  GnRHs are released to tell the testes to create more sperm. The GnRH production is increased when testosterone levels in the bloodstream drop. This means that if you artificially increase the level of testosterone in the bloodstream by using injections, patches or oral supplements, the body no longer produces as much GnRH. Without the GnRH, the testes are not signaled to increase sperm production and sperm count will fall.

Are Fertility Problems Caused by TRT Permanent?

In many cases, the reduced sperm count caused by taking TRT will not be permanent. In trials run by fertility clinics, patients who had experienced low sperm counts were able to reverse those findings after ceasing to take TRT. In other trials, a percentage of the men did not have sperm counts rise even after they stopped taking the prescription. In those trials, it was not entirely clear if the continued lack of sperm production was directly related to the supplements or if other factors also played a part.

What Can Patients Do to Protect Fertility Options?

Doctors who specialize in reproductive medicine may recommend that men do not start testosterone replacement therapy until they have had all their biological children. In other cases where that is not feasible, they encourage their patients to store sperm in a bank to ensure that they will not permanently compromise their chances of having biological children. There are also alternative hormone therapies that can be used instead of testosterone replacement therapy to address similar issues without causing the hormone feedback loop to reduce fertility. A reproductive endocrinologist can also give injections that will stimulate the body to produce its own testosterone, which will then have the same benefits as taking a direct testosterone replacement. As always, the best practice is to consult your medical providers about all the options available to you before deciding.