What testosterone injections actually do for fertility

Sperm production depends on a hormonal signal from the brain to the testicles. When your partner takes testosterone from outside the body, the hypothalamus and pituitary gland receive negative feedback and reduce the hormones that normally stimulate the testicles, lowering the testosterone concentration inside the testicles that sperm production actually depends on.¹

As a result, sperm production can fall substantially and, in some men, stop altogether, even though the testosterone level measured in the bloodstream may look normal or high. This can lead to a very low sperm count (oligospermia) or no detectable sperm in the semen (azoospermia).¹

This is why current NICE guidance specifically says that people concerned about their fertility should be asked whether they're taking prescription drugs such as testosterone-replacement therapy, among other medicines, and counselled on the potential effects.

It's worth not confusing this with the separate NHS point that hypogonadism, an abnormally low natural testosterone level, can itself be a cause of infertility. That's a different issue: the concern here is the effect of taking exogenous testosterone on the hormonal system that controls sperm production.³

Can you still get pregnant if your partner is on TRT?

Possibly, but it's less predictable than usual.

Some men taking TRT still have enough sperm in their semen to conceive naturally. Others have a very low sperm count, or no sperm detectable in their semen while they are taking treatment. There is no reliable way to tell which situation applies to your partner from his testosterone level, symptoms, appearance, or sex drive. A semen analysis is the practical way to find out what his sperm production currently looks like.

This is why doctors are cautious about testosterone therapy in men who are actively trying to have children. The AUA/ASRM male infertility guideline states that clinicians should not prescribe exogenous testosterone therapy to men interested in current or future fertility.¹

If your partner is already taking TRT and you are trying to conceive, the next step isn't guesswork, it's finding out where his fertility actually stands and discussing the treatment with the doctor who prescribes it.

He should not stop or change his testosterone dose on his own. Any decision to stop, switch, or modify treatment should be made with his prescribing clinician, taking both his medical needs and your fertility plans into account.

Does taking testosterone make you infertile, or just reduce fertility?

This is the bit that gets lost in forum threads and worst-case headlines.

For many men, TRT suppresses sperm production rather than causing a permanent loss of fertility. However, it's more accurate to say the effect is often reversible, not guaranteed to be completely or quickly reversible. The AUA/ASRM guideline notes that sperm production returns in most men after testosterone is stopped, but recovery can take months and, rarely, years, and some men may not fully recover their previous sperm production.

Research also suggests that recovery varies between individuals and can depend on factors such as baseline testicular function, duration of testosterone use, and age. In some men, stopping testosterone alone does not result in adequate recovery, and specialist fertility treatment may be needed.⁶

That's meaningfully different from saying TRT inevitably causes permanent infertility. But it's also why it's important not to assume fertility will immediately return after the last injection.

If your partner stops testosterone under his doctor's guidance, sperm production may start to recover, but this isn't necessarily a matter of a few weeks. Patience and follow-up testing can be important.

TRT isn't the same as anabolic steroid misuse, but the fertility effect can overlap.

You may have also come across the phrase "husband on steroids and pregnancy" while searching. It's worth untangling this, because TRT and anabolic steroid misuse aren't the same thing, even though both involve testosterone or testosterone-like hormones.

TRT is testosterone prescribed by a doctor for a medical reason, such as testosterone deficiency. Anabolic steroid misuse involves taking anabolic-androgenic steroids without appropriate medical supervision, often at doses or in combinations intended to increase muscle mass or athletic performance.

NHS guidance lists reduced sperm count and infertility among the possible effects of regular anabolic steroid misuse.⁵

Both exogenous testosterone and anabolic-androgenic steroids can suppress the hormonal system involved in sperm production, so neither should be assumed to be harmless to fertility, even though they aren't identical treatments.⁶

If there is any chance your partner is using anabolic steroids or other testosterone-like substances outside his prescription, it is important to tell his doctor. The exact substances, doses, duration of use, and combinations can all matter when assessing fertility and recovery.

How would you actually know if his fertility has been affected?

Sperm count, movement, and other semen characteristics aren't things you can reliably determine from how someone looks or feels. A semen analysis is the main initial test used to assess male fertility. It can identify problems such as a low sperm count or sperm that are not moving properly.⁴

Getting a semen analysis on the NHS

If you haven't conceived after a year of regular unprotected sex, NHS guidance recommends seeing your GP together, because fertility problems can affect either or both partners.

There are important exceptions to that one-year rule. NHS guidance recommends seeking help sooner if the woman is aged 36 or over, or if either partner has another reason to be concerned about fertility. Make sure your GP is aware of the testosterone injections and any other medicines or substances your partner takes, since current NICE guidance specifically flags testosterone-replacement therapy as something to raise when assessing factors that may affect fertility.²ˑ⁴

If he's already under an endocrinologist, urologist, or another clinician for his testosterone treatment, that's also a natural place to raise the fertility question. Fertility is worth discussing before and during TRT, not only after you've been trying unsuccessfully for a while.

What can help while you're trying to conceive:

A few practical steps tend to make more sense than simply waiting and hoping:

• Get the semen analysis done. It replaces guesswork with an actual picture of his current sperm production.
  
  

• Tell his prescribing doctor that you're trying to conceive. Whether testosterone should be continued, stopped, or replaced with another approach is a medical decision that needs to take his underlying diagnosis and fertility goals into account.
  
  

• Ask specifically about fertility-preserving options. Some men with testosterone deficiency may be candidates for treatments that stimulate their own testosterone production or support sperm production rather than relying on exogenous testosterone. The AUA/ASRM guideline discusses options such as hCG, selective oestrogen receptor modulators, and aromatase inhibitors in selected men, but these are specialist treatment decisions and aren't appropriate for everyone.¹
  
  

• Ask about sperm freezing before treatment or if fertility is currently preserved. Fertility preservation can be worth discussing with a fertility specialist, particularly if long-term testosterone treatment is expected.
  
  

• Give recovery time if he stops. Sperm production does not necessarily return immediately after testosterone is discontinued, and recovery can be prolonged and varies considerably between men.¹
  
  

• Don't rely on timing intercourse to overcome severely suppressed sperm production. Timing intercourse around ovulation remains relevant when sperm are present, but it cannot compensate for very low or absent sperm. If his semen analysis shows significant suppression, medical advice about the underlying problem matters more than trying to optimize individual cycles.
  
  

None of this is about panicking. It's about not spending months guessing about something that a semen analysis and a proper medical discussion can help clarify.

If he's just starting TRT and you're both thinking about kids:

If treatment hasn't started yet, you have the most options right now.

This is the ideal time to have the fertility conversation with his prescribing doctor, before treatment changes his sperm production. Current AUA/ASRM guidance says exogenous testosterone should not be prescribed to men interested in current or future fertility, and NICE specifically recommends asking about and discussing the potential fertility effects of testosterone-replacement therapy with people concerned about their fertility.²

Ask directly:

• What effect is this treatment expected to have on his sperm production?

• Would a semen analysis or sperm freezing make sense before treatment?

• Are there fertility-preserving alternatives appropriate for his underlying condition?

• If he is already taking TRT, what is the safest way to approach treatment if you want to conceive?

Don't assume that simply lowering the testosterone dose will preserve fertility. The issue is the effect of exogenous testosterone itself on the hormonal signals controlling sperm production, so any change in treatment should be planned with his clinician.¹

It's a completely reasonable conversation to have, and it's much better to have it before fertility becomes an urgent concern.

How the twoplus Applicator fits into this picture

Once you know where things stand, you can plan around it. Maybe his sperm count is lower than usual. Maybe timing is tighter, or you're simply trying to make the most of the fertile days you have. Either way, some couples look for a way to give each attempt the best possible chance without turning it into a clinical procedure.

This is where the twoplus Applicator can be a helpful addition to try alongside your GP's advice, not instead of it. It's designed to deposit sperm close to the cervix, at home, at a time that works for you both. It doesn't treat or reverse any underlying cause of reduced fertility, and it isn't a substitute for the semen analysis or the conversation with his doctor. But for couples working with lower sperm numbers or motility, making the most of each fertile window may make a real difference, and that's exactly what the Applicator is built to support.

If you do decide to try it, it's worth doing so alongside, not instead of, the medical picture. Know his semen analysis results first if you can, so you're making an informed choice about what's likely to help, rather than guessing.

Working with your fertility, not against it

Testosterone injections change the picture, but they don't necessarily mean giving up on trying.

The important thing is to understand what is happening to his sperm production, test it rather than assume, and involve the clinician managing his testosterone treatment. TRT can substantially suppress sperm production, but recovery is possible for many men after treatment is stopped, although the timeline and degree of recovery vary.¹

Getting the right information early gives you a much clearer basis for deciding what to do next, together.

Frequently asked questions

1. Does taking testosterone make you infertile?
   Not necessarily, but it can substantially reduce or even stop sperm production while someone is taking it. The effect varies between men, and a semen analysis is the practical way to assess his current sperm production.
   
   

2. Can you have kids while on TRT?
   Some men may still have enough sperm to conceive while taking TRT, but others develop very low sperm counts or azoospermia. Because you cannot reliably predict this from symptoms or testosterone levels, testing matters.
   
   

3. How long after stopping testosterone injections does fertility come back?
   There isn't one reliable timeline. Sperm production often recovers after stopping testosterone, but recovery can take months and, rarely, years, and some men do not fully recover their previous sperm production.⁶
   
   

4. Is TRT the same as anabolic steroid misuse when it comes to fertility?
   No. Medically prescribed TRT and anabolic steroid misuse are different situations. However, both exogenous testosterone and anabolic-androgenic steroids can suppress the hormonal signals needed for normal sperm production, and anabolic steroid misuse is also associated with reduced sperm count and infertility.⁵
   
   

5. Should he stop testosterone if we're trying for a baby?
   He should not stop or change his testosterone treatment without speaking to his prescribing clinician. However, fertility should be discussed with that clinician, since current AUA/ASRM guidance advises against exogenous testosterone therapy in men interested in current or future fertility.
   
   

Sources

1. AUA/ASRM – Diagnosis and Treatment of Infertility in Men (guideline, amended 2024): https://www.auanet.org/guidelines-and-quality/guidelines/male-infertility

2. NICE – Fertility problems: assessment and treatment (NG257): https://www.nice.org.uk/guidance/ng257

3. NHS – Infertility: Causes: https://www.nhs.uk/conditions/infertility/causes/

4. NHS – Infertility: Diagnosis: https://www.nhs.uk/conditions/infertility/diagnosis/

5. NHS – Anabolic steroid misuse: https://www.nhs.uk/conditions/anabolic-steroid-misuse/

6. Desai A, et al. – Understanding and managing the suppression of spermatogenesis caused by testosterone replacement therapy (TRT) and anabolic–androgenic steroids (AAS), Therapeutic Advances in Urology (2022): https://pmc.ncbi.nlm.nih.gov/articles/PMC9243576/