Editorial
Written byMen's Health Istanbul Editorial Team
Medical reviewer (awaiting sign-off)Prof. Dr. Bülent Alıcı
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The short answer
Yes. Testosterone therapy usually reduces sperm production, sometimes to the point where no sperm are found in the semen. Testosterone taken from outside the body tells the brain to stop sending the hormone signals the testicles need to make sperm. For this reason, clinical guidelines advise against testosterone therapy for men who are trying for a child or plan to in the near future. In most men sperm production recovers after stopping, typically over months, but how long it takes varies and recovery cannot be predicted for any one man.
Key takeaways
- Testosterone therapy suppresses the brain's signals to the testicles and usually lowers sperm production.
- Guidelines advise against testosterone therapy for men who want children soon.
- Sperm production usually recovers after stopping, but the time it takes varies.
- Men with low testosterone who want to preserve fertility should discuss the alternatives with a specialist before starting treatment.
Why does testosterone lower sperm count?
Sperm production depends on a chain of hormone signals. The pituitary gland at the base of the brain releases two hormones, LH and FSH. LH tells the testicles to make testosterone, and FSH, together with the high levels of testosterone inside the testicles, drives sperm production.
When testosterone is given as a gel, injection or implant, the brain senses plenty of testosterone in the blood and turns down LH and FSH. The testicles then make less of their own testosterone and much less sperm. The level in the bloodstream may look healthy while the level inside the testicles, where sperm are made, falls.
This is also why the testicles can become a little smaller during treatment.
Can testosterone therapy make you infertile?
It can reduce fertility substantially while you are taking it. In some men the sperm count drops to zero, a condition called azoospermia. For this reason, both the American Urological Association and the Endocrine Society advise that testosterone therapy should not be prescribed to men who are trying to conceive or who hope to in the near future.
However, it is not a reliable contraceptive either. Some men continue to produce sperm, so it should never be relied on to prevent pregnancy.
Does sperm production come back after stopping testosterone?
In most men, yes. Some of the clearest evidence comes from research into testosterone-based male contraception, where healthy men were given hormones deliberately to suppress sperm and then stopped. An analysis of these studies published in The Lancet in 2006 found that most men's sperm counts recovered after stopping, typically within months.
The time to recovery varied from man to man, and those volunteers were generally young and healthy. Men treated for low testosterone are often older and may have other reasons for reduced fertility, so recovery in real-world patients can be slower or less complete. Nobody can promise how any one man will respond.
What are the options if I have low testosterone and want children?
Low testosterone and a wish for children are not mutually exclusive, but they need planning. Options a specialist may discuss include:
- Delaying testosterone therapy until the family is complete, while addressing weight, sleep and other contributors to low levels.
- Medicines that stimulate the body's own production. Some treatments work by boosting the brain's hormone signals rather than replacing testosterone, which can raise testosterone without switching off sperm production. They are not suitable for everyone, and a specialist decides whether they are appropriate.
- Checking fertility first. A semen analysis before treatment gives a baseline, and some men choose to store sperm.
If you are already on testosterone and want to conceive, do not simply stop or change treatment without advice. A specialist can plan how to come off it and monitor recovery.
What about anabolic steroids?
Anabolic steroids used for muscle building act on exactly the same hormone system, often at far higher amounts than medical treatment. They are a recognised cause of low sperm counts and, after stopping, of low testosterone while the body's own production restarts. Being open with a doctor about past use helps them give accurate advice.
What to take away
Testosterone therapy has a real place for men with confirmed deficiency, but it and fertility pull in opposite directions. If there is any chance you want children, raise it before treatment starts. For the bigger picture, see our piece on male fertility after 40.
Questions men also ask
Is testosterone a contraceptive?
No. Although it lowers sperm production, it does not do so reliably enough in every man to be used as contraception on its own.
Do anabolic steroids affect fertility in the same way?
Yes. Anabolic steroids used for bodybuilding act on the same hormone system and can suppress sperm production, often at higher doses than medical treatment.
Should I have a semen analysis before starting testosterone?
If you might want children in future, it is worth asking your doctor about checking your fertility before treatment begins.
Sources & further reading
- Journal of Urology Evaluation and Management of Testosterone Deficiency: AUA Guideline (opens in a new tab) (2018) Mulhall JP, et al.
- Journal of Clinical Endocrinology & Metabolism Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline (opens in a new tab) (2018) Bhasin S, et al.
- The Lancet Rate, extent, and modifiers of spermatogenic recovery after hormonal male contraception: an integrated analysis (opens in a new tab) (2006) Liu PY, et al.
- EAU EAU Guidelines on Sexual and Reproductive Health (opens in a new tab) (2024) European Association of Urology
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This article is general health information. It does not replace an individual medical consultation, examination or diagnosis. Read our editorial policy and medical review policy.
