Testosterone replacement therapy (TRT) is a common treatment for easing symptoms of low testosterone (hypogonadism) in men. These symptoms include erectile dysfunction (ED), low libido, fatigue, muscle loss, and depression.
Testosterone replacement therapy (TRT) is a common treatment for easing symptoms of low testosterone (hypogonadism) in men. These symptoms include erectile dysfunction (ED), low libido, fatigue, muscle loss, and depression.
According to research, TRT has a high success rate in improving muscle mass and strength, fat mass, bone density, sexual function, mood, and general well-being.
Despite the many positive effects of TRT, though, it also comes with risks, one of which is male factor infertility. Fortunately, there are alternative low testosterone treatment options available and some precautions you can take before starting TRT if fertility is a concern for you.
Below, learn more about how testosterone use can impact fertility, whether it’s possible to maintain fertility on TRT, and alternative options to discuss with your healthcare provider.
Testosterone is the quintessential male sex hormone, or androgen, and it has a number of big jobs: Pre-birth, it drives the development of your penis, prostate, and testicles. During puberty, it helps you develop your secondary sexual characteristics, like body hair and a deeper voice. Testosterone also increases the size of your muscles and bones, regulates your sex drive, and supports red cell production.
When it comes to male fertility, testosterone plays a crucial role.
In fact, research shows that testosterone is required for spermatogenesis, or the process of producing sperm, given that sperm production is reliant on androgen action within the testes.
Here’s how it works:
The pituitary gland secretes luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in response to the release of gonadotropin-releasing hormone (GnRH) from the hypothalamus in the brain.
LH then stimulates the Leydig cells in the testes to produce testosterone, while FSH stimulates the Sertoli cells to make sperm.
Though FSH is the main player when it comes to sperm production, without testosterone and its receptor, spermatogenesis can’t be completed, resulting in male infertility.
A urologist or other healthcare provider may prescribe testosterone replacement therapy to help resolve symptoms of low testosterone.
Some of the most common symptoms of low T include:
Low sex drive
Low sperm count and quality
Testicular shrinkage
Loss of muscle mass
Decreased bone density
Increased body fat
Fatigue
Sleep disturbances
Hot flashes
Depression
Memory trouble
Reduced red blood cell count (anemia)
Less body hair
Gynecomastia (male breast development)
TRT comes in many forms, including testosterone injections, gels, creams, pellets, patches, and oral medications.
A man may be diagnosed with low testosterone if his levels are below 300 nanograms per deciliter of blood (ng/dL) and he exhibits aforementioned symptoms of low T. However, a man with normal testosterone levels can still be diagnosed with low testosterone and prescribed treatment if he is dealing with persistent symptoms of testosterone deficiency.
The causes of low testosterone vary and depend on the type of hypogonadism you have: primary (originating in the testicles) or secondary (originating in the brain).
Causes of primary hypogonadism include:
Klinefelter syndrome (a chromosome abnormality)
Testicular injuries
Undescended testicles
Cancer treatments
Infections like mumps orchitis
Causes of secondary hypogonadism include:
Genetic conditions like Kallmann syndrome
Pituitary disorders
Obesity
Inflammatory disorders
HIV/AIDS
Anabolic steroid use
It may seem strange that taking exogenous testosterone can harm your fertility, given that the treatment increases your testosterone levels, which is essential for sperm production. Even more, testosterone therapy amps up your libido and supports erectile function—both of which are positive for your reproductive health.
But here’s the thing: TRT shuts down your body’s natural testosterone production by tampering with the hypothalamic-pituitary-gonadal (HPG) axis. Though TRT delivers synthetic testosterone into the bloodstream, it signals the brain to suppress LH and FSH, leading to a drop in intra-testicular testosterone and halting sperm production. As a result, TRT can lower sperm count and significantly reduce fertility.
Other side effects and risks of TRT:
Redness, itching, or a rash if you use topical TRT
Swelling, bruising, and pain if you use testosterone pellets or injections
Allergic reactions
Worsened sleep apnea
Increase in red blood cell count
Gynecomastia (male breast development)
Some research has shown that regular testosterone use can suppress spermatogenesis and sometimes lead to azoospermia (zero sperm in semen) in as little as 10 weeks.
Research has concluded that 67 percent of men recover normal sperm counts by six months after stopping TRT, 90 percent recover by 12 months, and nearly 100 percent recover by 24 months.
However, for men who use high doses of testosterone or stay on TRT for long periods of time, the reversal may take longer or may not be achievable. Thirty percent of men, particularly older individuals or those on TRT for longer, may experience incomplete recovery after one year.
Taking the following additional medications (under the care of a provider) may help some maintain fertility on TRT:
Human chorionic gonadotropin (hCG). Due to its ability to stimulate Leydig cells without compromising the HPG axis, hCG is sometimes used in combination with testosterone supplementation to preserve spermatogenesis. In one small study of men receiving both TRT and low-dose hCG, none became azoospermic after one year, and there were no significant changes in semen volume, sperm concentration, or motility.
Selective estrogen receptor modulators (SERMs). SERMs like clomiphene citrate (Clomid®), tamoxifen citrate, and enclomiphene citrate can potentially preserve fertility by increasing LH and FSH production. SERMs are often prescribed on their own to men who want to improve their testosterone without impairing their fertility. Some studies have shown that SERMs can increase testosterone levels and improve symptoms as effectively as exogenous testosterone.
Aromatase inhibitors. Like SERMs, aromatase inhibitors like anastrozole and letrozole are often prescribed as a monotherapy in men with low T who wish to preserve their fertility. While more research is needed, one study in men with Klinefelter syndrome found that combining daily anastrozole with TRT led to a 70 percent success rate in retrieving sperm through surgery.
Even if you plan to combine TRT with one of the aforementioned therapies, it’s wise to freeze and store your sperm beforehand if you hope to have kids in the future. This can safeguard your fertility if you don’t plan on coming off TRT or if you aren’t able to fully recover after stopping TRT.
Frozen sperm can be used in fertility treatments like intrauterine insemination (IUI) or in vitro fertilization (IVF) to assist in conception.
While any form of TRT comes with risks, there are studies that show some forms may be less impactful on your fertility than others.
For instance, one study found that testosterone patches led to azoospermia in 24 percent of subjects, while separate research concluded that intramuscular TRT injections resulted in a 93 to 98 percent rate of azoospermia after six months of treatment.
Nasal testosterone may also help improve low T symptoms while preserving fertility. One study on short-acting nasal testosterone gel found that over six months, the intervention effectively raised testosterone levels while preserving sperm count in most men with hypogonadism. About 91 percent reached normal testosterone levels, and nearly 94 percent maintained healthy sperm counts.
If you’re considering starting TRT but want to preserve your fertility, here’s what you should know:
TRT can lower sperm count, but there are supplemental treatments that may help maintain your fertility. TRT can inhibit sperm production, but medications like hCG, SERMs, and aromatase inhibitors may help maintain fertility when either used in conjunction with TRT or on their own. For added security, sperm freezing before starting TRT is a smart precaution.
Some forms of TRT may affect your fertility less than others. Transdermal patches and short-acting nasal testosterone have been shown to be potentially less harmful to fertility than TRT injections.
Male factor infertility induced by TRT isn’t always permanent. Fertility often returns after stopping TRT, with most men recovering sperm production within six to 24 months. However, older age, high doses, or long-term use can make recovery slower or unsuccessful.
The decision to try TRT isn’t one to make lightly. Always talk to your healthcare provider about your long-term goals, especially if one of them is parenthood, before starting any hormone therapy.
Further, don’t underestimate potential positive impact lifestyle changes can have on your testosterone levels, whether you choose TRT or another low testosterone protocol. A balanced diet, regular exercise, weight loss, better sleep, and reducing stress can all help improve natural testosterone production.
For more tips, check out which foods support testosterone, learn the truth about so-called testosterone boosters, and explore the connection between low testosterone and ED.
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