Blog
Sep 9, 2026
Testosterone is the primary male sex hormone and plays a crucial role in sperm production and reproductive health. The hormone is produced mainly in the testicles and is essential for the normal development and maturation of sperm cells.
If testosterone levels are too low, it can affect sperm production, libido and the ability to achieve a pregnancy.
Testosterone is a hormone produced primarily in the testicles. Its production is regulated by signals from the brain and is part of the body’s hormonal system.
Testosterone has several important functions, including:
Stimulating sperm production
Influencing sex drive (libido)
Supporting normal erectile function
Maintaining muscle mass and bone density
Contributing to male sexual development
A balance between testosterone and other reproductive hormones is important for fertility.
Adequate levels of testosterone within the testicles are required for normal sperm production. If testosterone levels are too low, sperm production may decrease or, in some cases, stop altogether.
Low testosterone levels can affect:
Sperm count
Sperm maturation
Sperm quality
Male fertility
In some men, low testosterone levels are first identified during a fertility evaluation.
Low testosterone levels can cause a variety of symptoms, although some men experience no obvious signs.
Common symptoms may include:
Reduced sex drive
Fatigue and low energy levels
Erectile dysfunction
Decreased muscle mass
Low mood or depression
Reduced fertility
If sperm production is affected, difficulty achieving a pregnancy may be the first indication of a hormonal imbalance.
Between 30 and 50 percent of fertility problems experienced by couples involve male factors. Hormonal imbalances are one of several factors that can affect sperm production.
However, low testosterone is not always the cause of infertility. Many men with normal testosterone levels may have impaired sperm quality, while others with lower testosterone levels may still maintain adequate sperm production.
As part of a fertility assessment, hormone testing can be used to evaluate testicular function and sperm production.
Common tests include:
Testosterone
FSH (follicle-stimulating hormone)
LH (luteinizing hormone)
SHBG (sex hormone-binding globulin)
Prolactin
Hormone testing is often combined with a semen analysis, which evaluates sperm count, motility and morphology.
By combining these results, the physician can gain a clearer understanding of the factors affecting fertility.
Many people are unaware that testosterone therapy can have a negative impact on fertility. Although testosterone is essential for normal sperm production, this does not mean that additional testosterone improves fertility. In fact, external testosterone therapy can reduce the body’s own sperm production.
Hormone production is regulated through a complex interaction between the brain, the pituitary gland and the testicles. When testosterone is administered in the form of gels, injections or tablets, the brain detects that testosterone levels are already sufficient. As a result, it reduces the production of the hormones that normally stimulate the testicles to produce both testosterone and sperm.
When these hormonal signals decrease, sperm production can be significantly impaired. In some men, sperm counts decline substantially, while in others sperm production may temporarily stop altogether. The risk is often greater with higher doses or long-term treatment.
Many men using testosterone therapy experience increased energy levels, improved libido and an enhanced sense of wellbeing. However, fertility can be negatively affected without any obvious symptoms. This means that sperm quality may decline even when an individual feels healthy and has normal testosterone levels in the bloodstream.
In most cases, sperm production recovers after testosterone therapy is discontinued. However, recovery can take several months and, in some cases, up to one or two years depending on the duration of treatment, dosage and individual factors. Some men may require additional hormone treatments to stimulate testicular function and restart sperm production.
For men planning to have children, it is therefore important to discuss any testosterone therapy with a physician before starting treatment. In certain cases, alternative therapies may help preserve or stimulate sperm production while also addressing symptoms of low testosterone.
If you currently use testosterone or have previously used anabolic androgenic steroids and are experiencing difficulty conceiving, a fertility evaluation including a semen analysis can provide valuable information about how fertility may have been affected and what treatment options are available.
Several lifestyle factors can influence both testosterone levels and sperm production.
Important factors include:
Overweight and obesity
Smoking
Excessive alcohol consumption
Stress
Lack of sleep
Physical inactivity
A healthy lifestyle can contribute to improved hormonal balance and create more favourable conditions for sperm production.
If you and your partner have been trying to conceive without success, or if you are experiencing symptoms that may be related to abnormal testosterone levels, it may be appropriate to undergo a fertility assessment.
An evaluation can help identify hormonal or other medical causes affecting sperm production and guide appropriate treatment.
If you would like to learn more about how testosterone affects sperm production and fertility, a fertility assessment can provide answers. Through a comprehensive evaluation, our specialists can assess your reproductive health and help create the best possible conditions for achieving fatherhood.
