TRT and Fertility: The Definitive Guide

Does TRT affect fertility?

Yes. Testosterone replacement therapy (TRT) switches off the brain signals that tell the testicles to make sperm, so sperm counts fall, often to zero. All forms of testosterone lower these signals, some more than others. For most men it reverses after stopping, but recovery takes months, and guidelines say not to use testosterone while trying to conceive. [7], [6], [16]

Here is why. The testicles do two jobs: they make testosterone and they make sperm. Both depend on two hormones from the pituitary gland at the base of the brain. LH (luteinizing hormone) tells the testicles' Leydig cells to make testosterone, and FSH (follicle-stimulating hormone) supports the Sertoli cells that nurse developing sperm. Sperm production needs both FSH and a very high testosterone level inside the testicle, about 80 to 100 times the level in the blood. [17], [11]

When testosterone comes from an injection, gel or capsule, the brain senses plenty of it and turns LH and FSH down. The testosterone in your blood can look perfect while the testosterone inside the testicle falls sharply: by 94% within 3 weeks in healthy men given weekly injections. That is why a normal testosterone result says nothing about sperm. [11], [1]

The newer US labels, such as those for Xyosted and AndroGel 1.62%, say: "Reduced fertility is observed in some men taking testosterone replacement therapy. The impact on fertility may be irreversible." The UK label for Testogel describes the suppression as reversible. Most men do recover; the US wording reflects the minority who do not fully recover. [1], [18], [19]

TRT and fertility: the key numbers

This table shows what each major clinical guideline says about testosterone for men who want children, how quickly each expects sperm to return, and which alternatives it names. Checked September 2026.

[6], [7], [2], [8], [20], [21], [22], [23], [24], [25], [17], [26]

Every major guideline says not to use testosterone while trying to conceive. They differ in two places: whether men who want children later may start TRT after counselling (the US infertility guideline allows it; the EAU and EAA say no when fatherhood is wanted), and how fast sperm returns (the AUA says two-thirds within 6 months; the BSSM says 60–70% within 12 months). [7], [8], [24], [6], [21]

Why do guidelines disagree about men who want children later?

Because no study has followed men who start TRT young and try for children years later. The US infertility guideline treats it as an informed choice after counselling; the European guidelines put the risk of slow or incomplete recovery first; the Endocrine Society says not "in the near term", with sperm banking if plans are uncertain. On adding hCG to TRT they also split: the AUA testosterone guideline says doctors may offer it, and the later US infertility guideline says the evidence is too limited (see hCG). [7], [8], [2], [6]

What do semen analysis numbers mean?

A semen analysis is the test that shows sperm production. The World Health Organization (WHO) publishes reference values from men whose partners became pregnant within a year. A result below these limits is not a diagnosis of infertility on its own, and many men below them still father children. [27], [7]

[27]

The total motile count, the number of moving sperm in the whole sample, decides the fertility treatment options: insemination (IUI) usually needs at least 5–10 million, because about half the sperm are lost in preparation, while IVF with ICSI needs only a few. [7]

How to get a fair result. The Endocrine Society advises at least two analyses several weeks apart, each after at least 48 hours without ejaculation (WHO uses 2–7 days). [2], [27]

Units. Sperm counts appear as million per mL (concentration) or million per sample (total). Testosterone appears in ng/dL or nmol/L; the testosterone unit converter switches between them.

How does testosterone switch off sperm production?

Through the hormone chain from brain to testicles, called the HPG axis (hypothalamus, pituitary, gonads). The brain's hypothalamus sends pulses of GnRH, the pituitary answers with LH and FSH, and the testicles answer with testosterone and sperm. Testosterone then feeds back to the brain to slow the chain down. This is established human physiology, and the US labels describe exactly this feedback. [1], [17]

• LH falls first, then testosterone inside the testicle. In a 3-week trial of healthy men given testosterone enanthate 200 mg a week, testosterone inside the testicle fell by 94%, while blood testosterone rose. [11]
• FSH falls too. Without FSH and the high local testosterone, the Sertoli cells cannot support sperm development. The US labels put it this way: at large doses, spermatogenesis may be suppressed through feedback on FSH. [1], [17]
• Sperm take about 64 days to make (spermatogenesis). Studies that labelled new sperm cells found they reached the semen after about 64 days on average (range 42–76 days). That is why a semen analysis shows the effect of any change about 2–3 months later, both when sperm counts fall and when they recover. [29], [30]
• The testicles shrink. In healthy men given enanthate 200 mg weekly for 4 months, testicle volume fell by about 19%; it returned to normal after stopping. No study has measured this in men on usual TRT doses. [31]

Why does the cause of low testosterone matter?

Because it decides what can restore sperm later. In secondary hypogonadism, the brain and pituitary send too little LH and FSH, but the testicles themselves can work, so hormone treatment that replaces the missing signals can start sperm production. In primary hypogonadism, the testicles themselves are the problem, and the Endocrine Society says gonadotropin treatment does not restore fertility; options then include donor sperm, adoption, or IVF using sperm found in the semen or extracted from the testicle. [2], [20] The primary vs secondary hypogonadism guide explains how the two are told apart.

What does the research show?

Testosterone suppresses sperm reliably and, in most men, reversibly. The clearest numbers come from male contraception trials in healthy volunteers, which used research doses. Studies of men on prescribed TRT are smaller, but they point the same way, with slower recovery after long use. [3], [9], [5]

How fast and how completely does testosterone suppress sperm?

Within about 2–3 months in most men. These trials tested testosterone as a male contraceptive in healthy, fertile volunteers, at doses above usual TRT:

The research dose of 200 mg a week is higher than most TRT prescriptions, but men on prescribed testosterone can show similar results: at a Canadian infertility clinic, 88.4% of the men using testosterone had no sperm at all while on it, and 12% of them had been prescribed it to treat infertility. [5]

Does the form of testosterone matter?

It changes how strongly LH and FSH are switched off, but no form has been shown to be safe for fertility. A 2021 review of 8 studies (793 men) compared the fall in FSH and LH by form:

[16]

Doserly

How much each form lowered FSH and LH

Average fall from each man's starting level (review of 8 studies, 793 men).

Bars run from 0% to 100% fall; the darker bar is FSH, the lighter bar is LH.

Long-acting injections (only 16 men)

FSH fell 86.3%; LH fell 71.8%

Daily gels or patches (471 men)

FSH fell 60.2%; LH fell 59.2%

Nasal testosterone (306 men)

FSH fell 37.8%; LH fell 47.3%

Every form lowered both signals. Hormones only: none of these studies measured sperm.

• Nasal testosterone. In a 6-month study of Natesto three times a day, the total motile count stayed above 5 million in 93.9% of men still in the study, but there was no comparison group, only 33 of the 60 men who enrolled were assessed at 6 months, and the registry results list one man whose sperm disappeared and three with severe drops, and a case report describes sperm falling on Natesto. A marker of testosterone inside the testicle fell by 33.3% on nasal testosterone and 65.3% on injections. The US infertility guideline says nasal testosterone should not be used routinely by men trying to conceive. [34], [35], [36], [37], [7]
• Oral testosterone undecanoate. On Jatenzo, LH and FSH fell by about 70%; on Tlando, only 41% of men kept LH and 40% kept FSH in the normal range. The Jatenzo and Tlando studies did not measure sperm, and we found no study of sperm on oral testosterone taken on its own. [38], [39] See oral testosterone.
• Gel. Long-term gel suppresses LH and FSH, and in two trials that compared it with enclomiphene, AndroGel 1.62% markedly reduced sperm production. [40], [41]

"Short-acting" means less suppression on average, not fertility-safe.

How long does sperm take to come back after stopping?

Most men recover within about a year, but it depends on how long and how much testosterone was used, and some take much longer.

In the pooled contraception trials, older men and Asian men recovered faster, as did men with shorter treatment and shorter-acting preparations. On average, recovery levelled off at about 85% of the men's starting concentration. [9], [32]

Doserly

When sperm fall on testosterone, and when they come back

On testosterone

Weeks since the first weekly injection (Ly 2005, model of WHO contraception trial data).

1. About 10 weeks

   Sperm below 3 million per mL, on average.

2. About 13 weeks

   Below 1 million per mL, on average.

After stopping

Months since the last dose (Liu 2006, pooled contraception trials, 1,549 healthy men).

1. 6 months

   67% back to 20 million per mL.

2. 12 months

   90% back to 20 million per mL.

3. 16 months

   96% back to 20 million per mL.

4. 24 months

   100% back to 20 million per mL.

5. Median 3.4 months

   Half of the men in those trials had recovered by then.

6. Median 8 and 8.5 months

   Men on TRT who became infertile, in two small clinic series (20 and 8 men): normal counts after stopping.

Each point comes from one study; no curve is drawn between them. Men on TRT for years can take longer.

These are averages, mostly from volunteers who used testosterone for months. Men on TRT for years, or with fertility problems before starting, cannot assume the same timeline; the BSSM notes that about 7% of men may be infertile for other reasons. [21]

Do fertility medicines speed up recovery?

They are widely used, but no randomized trial has compared them with simply stopping and waiting. All the evidence comes from treatment series:

In the Kohn series, each extra year of age lowered the 12-month chance of recovery by about 1.7 percentage points, and each extra year of testosterone use by about 3.1 points. It was a model built from 66 men, so it describes a trend, not an individual's odds. [46]

Is TRT's effect on fertility permanent?

Usually not, but for some men it may be. Most men regain sperm after stopping, yet the US infertility guideline says some never fully recover and remain infertile or subfertile, and newer US labels say the effect "may be irreversible". No study gives a reliable rate of permanent loss after prescribed TRT. [7], [1], [9]

Is TRT safe if you want children?

Not while you are trying to conceive: every guideline advises against it. For men who want children later, it is a trade-off to plan with a clinician: bank sperm first, choose an alternative that keeps LH and FSH working, or stop in good time. [6], [2], [7]

Can you get someone pregnant while on TRT? Is TRT birth control?

Yes, you can, and no, it is not reliable birth control. Even in the WHO contraception trials, where healthy men were monitored closely, pregnancies happened:

• When men had no sperm at all, there was 1 pregnancy in 1,486 months of use. [4]
• When counts were low but not zero (0.1–3 million per mL), there were 4 pregnancies in 49.5 person-years, a rate of 8.1 per 100 person-years, against none in 230.4 person-years of azoospermia. [48]
• In a trial of monthly undecanoate injections in 1,045 men, 4.8% never suppressed enough and 9 pregnancies occurred. [33]

Men on TRT are not monitored with regular semen tests, so nobody knows whether they are in the "zero" or the "low" group. The Society for Endocrinology says it cannot be assumed that testosterone will cause infertility, and contraception should always be discussed. [17]

Can TRT cause birth defects or miscarriage?

We found no study of babies conceived while the father was on prescribed testosterone, so whether it changes the risk of birth defects or miscarriage is unknown. The known pregnancy risk is different: testosterone gels and solutions carry a US boxed warning because skin contact can pass testosterone to children, and UK labels say pregnant women must avoid contact with the application site. See testosterone gel. [18], [19]

Who should be especially cautious?

• Men trying to conceive now or within about a year. Every guideline advises against starting testosterone. [2], [7]
• Young men and men who may want children later. Fertility plans should be discussed before TRT starts, with a semen analysis first when subfertility is suspected. [6], [17]
• Men with primary hypogonadism. Hormone treatment usually cannot restart sperm production when the testicles themselves are badly damaged. [2], [20]
• Men who have used anabolic steroids. Recovery is slower and less certain: in one study of amateur athletes, 34% still had a low sperm count a year after a cycle began. See TRT vs steroids. [49]
• Men with a pregnant partner or young children at home using a gel, because of skin transfer. [18]
• Drug-tested athletes. Testosterone, hCG and the fertility tablets are all prohibited in sport. [15]
• Under-18s. Testosterone for teenagers, for example for delayed puberty, belongs only in specialist care.
• Women. This guide is written for men. Testosterone for women uses different doses and products; see testosterone therapy for women.

Which medicines and supplements affect sperm?

• Anabolic steroids switch off sperm production the same way, often more strongly. [49]
• Finasteride and dutasteride (for hair loss or an enlarged prostate). In a 1-year trial in 99 healthy men, total sperm count fell by 34.3% on finasteride 5 mg and 28.6% on dutasteride at 26 weeks; the fall was no longer significant at 52 weeks and reversed after stopping. That study used the 5 mg prostate dose of finasteride. [50]
• Opioid painkillers taken long term lower testosterone themselves: total testosterone was below normal in 74% of 54 men on long-acting opioids. [51]
• Supplements have not been shown to protect sperm on TRT (see supplements).

Bring a full list of everything you take, including supplements, to a pharmacist or prescriber. Checked September 2026.

Is testosterone legal, and are fertility medicines allowed in sport?

Checked September 2026. Rules differ by country and change often.

• United States. Testosterone is a Schedule III controlled substance. hCG is an approved prescription medicine (Pregnyl, Novarel, a generic and Ovidrel); since March 23, 2020 it has been regulated as a biologic, so pharmacies cannot compound it. Enclomiphene is not FDA approved (FDA lists it as under evaluation for compounding), and kisspeptin-10 is listed among compounding substances with significant safety risks. [14], [52], [53], [54]
• Canada. Testosterone is a Schedule IV controlled substance. Two hCG products (Pregnyl and a generic) are marketed. [55], [56]
• United Kingdom. Testosterone and hCG are Class C controlled drugs. The two long-standing hCG brands, Pregnyl and Choragon, are discontinued, and hospitals now use an unlicensed imported product. [57], [58]
• Australia. Testosterone is a Schedule 4 prescription-only medicine. Recombinant hCG (Ovidrel) has been subsidised on the PBS for some uses in men since July 1, 2023, prescribed by specialists. [59], [60], [61]
• European Union. The European Medicines Agency refused a marketing authorisation for enclomiphene in 2018. [62]
• Sport. The World Anti-Doping Agency (WADA) prohibits testosterone at all times; hCG, LH, gonadorelin and kisspeptin in men; and aromatase inhibitors and SERMs such as clomiphene and tamoxifen. Its 2027 list, published in September 2026, keeps these bans. [15], [63]

What do guidelines say to do?

Plan before starting, do not start while trying to conceive, and, for men already on TRT who want children, stop with a plan or see a fertility specialist. This section describes the choices clinicians weigh; it is not a personal plan. [6], [7], [2]

The AUA testosterone guideline says: "For men already on exogenous testosterone who are planning future reproduction, testosterone cessation should occur in advance of initiation of any effort to conceive." [6]

How do specialists restart sperm production?

For men whose low LH and FSH are the underlying problem, the approved medicines are hCG (acting like LH) and FSH, often in that order. The labels describe schedules for men with pituitary-related hypogonadism, not specifically for recovery after TRT:

These are label regimens for a medical condition, not TRT-recovery protocols, and specialists adjust them to each man. Results are encouraging but slow: in a 2026 series of 35 men with pituitary-related azoospermia, sperm appeared in 27 (77%) after a mean of 12 months, and 18 became fathers. The Society for Endocrinology notes that earlier testosterone does not reduce the later response to gonadotropins. [69], [17]

What happens when you stop TRT to try for a baby?

Your own testosterone does not restart straight away. LH and FSH take weeks to months to recover, and after 2 years of long-acting injections in T4DM they were still recovering 12 months later. In between, many men have low testosterone and its symptoms: low energy, low sex drive and low mood. For men stopping anabolic steroids, the Society for Endocrinology notes that no randomized study shows whether hCG or SERMs ease those symptoms. [44], [17]

This is the trade-off many men face: stop and feel worse for a while, or stay on testosterone with a specialist fertility plan. Guidelines give no set waiting time for prescribed TRT. For anabolic steroid users, the EAU suggests waiting 6–12 months after stopping before starting SERMs or gonadotropins, and notes that sperm usually improves within 6–12 months of stopping. [20] The stopping TRT guide covers what happens to symptoms, hormones and blood counts after stopping.

Can you stay on TRT and keep your fertility?

Sometimes, but nothing has been proven to protect it. The most studied approach is adding hCG to testosterone, and the direct evidence is one 3-week hormone study and one small series without a comparison group; larger studies measured hormones only or treated men who had already lost sperm. The US infertility guideline says the evidence is too limited to recommend it. [11], [70], [7]

Does hCG keep you fertile on TRT?

It protects a hormone signal inside the testicle; whether it protects fertility is not proven.

The 2025 international consensus (ICSM) describes hCG with a lowered testosterone dose as an established off-label practice, but notes that no trials have proven it safe or effective. The schedules used, and how IU convert to syringe units, are in the hCG guide. [23]

Do gonadorelin or enclomiphene work alongside TRT?

No study has tested gonadorelin, enclomiphene or kisspeptin for fertility in men who stay on testosterone. Gonadorelin copies GnRH, and enclomiphene also works through the pituitary, which testosterone is already switching off. Kisspeptin acts higher up the chain. None is an approved medicine for this use in the US. The hCG, gonadorelin and enclomiphene comparison sets them side by side. [54]

Is there a form of testosterone that doesn't affect fertility?

No. Nasal testosterone switched off FSH and LH least on average and kept sperm counts in most men in one uncontrolled study, but some men still lost sperm, and the US infertility guideline advises against routine use by men trying to conceive. In a series of 27 men who switched from long-acting TRT to Natesto, all had sperm return, but there was no comparison with simply stopping, and the author disclosed speaker fees from the maker. See how the forms compare. [34], [35], [73], [7]

If a specialist does combine testosterone with hCG or a tablet, each medicine runs on its own days and amounts, and changes to one are easy to lose track of over months of semen tests.

What are the alternatives to TRT for men who want children?

Treatments that raise your own testosterone by stimulating the testicles or the pituitary, instead of replacing it: SERM tablets, hCG on its own, sometimes aromatase inhibitors, and weight loss where weight is the cause. They only work when the testicles can respond, so they usually help little in primary hypogonadism, especially when the testicles are badly damaged. None of the tablets is approved for low testosterone in men. [7], [8], [20]

Doserly

Where each option acts in the brain-to-testicle chain

The chain: hypothalamus → GnRH → pituitary → LH and FSH → testicle (Leydig cells make testosterone; Sertoli cells support sperm-making). Testosterone and estradiol in the blood feed back and turn the signals down.

Kisspeptin

Hypothalamus: acts above GnRH

Gonadorelin

GnRH signal: copies GnRH

Testosterone therapy

Feedback loop: adds to it, so LH and FSH go down

SERMs (clomiphene, enclomiphene)

Feedback loop: blocks estrogen's feedback, so LH and FSH go up

Aromatase inhibitors

Feedback loop: less estradiol, so LH and FSH go up

hCG

Testicle, Leydig cells: acts like LH

FSH or hMG

Testicle, Sertoli cells: FSH acts on the Sertoli cells; hMG also has LH activity, so it acts on the Leydig cells too

Shows where each option acts, not how well it works. Testosterone therapy is the only one that turns the signals down.

Clomiphene or enclomiphene instead of TRT?

Clomiphene raises testosterone about as much as testosterone gel, though in a few small studies sex drive improved less than on TRT. A 2025 meta-analysis of randomized trials found clomiphene or enclomiphene raised total testosterone by about 274 ng/dL (about 9.5 nmol/L) more than placebo, while also raising LH and FSH. A 2026 meta-analysis (11 studies, 1,512 men) found clomiphene raised testosterone about as much as gel; in the 3 studies (199 men) that measured libido, scores were lower on clomiphene than on TRT. [12], [79]

• Clomiphene is approved only for ovulation problems in women; its label says no adequate studies show it works for male infertility and notes reports of testicular tumors and breast growth in men. In 400 men treated long term, 88% of those on it for more than 3 years had normal testosterone and 8% reported side effects such as mood change or blurred vision. The Endocrine Society says its efficacy and safety are not proven in randomized trials. [74], [80], [2]
• Enclomiphene kept sperm concentration normal over 16 weeks in two phase 3 trials, while AndroGel 1.62% markedly reduced it. It is not risk-free for sperm: in two 12-week registry trials, sperm concentration fell by half or more in 14.2% of men on enclomiphene, against 2.6% and 4.3% on placebo. It is not approved in the US or EU, and a 2026 UK position statement does not recommend routine use outside specialist settings. [41], [81], [62], [82]

The EAU notes that SERMs may raise the risk of blood clots and that long-term use of SERMs or aromatase inhibitors can lower bone density. [8]

What about hCG on its own?

It raises testosterone when the testicles can respond: in a randomized trial of 282 men who wanted to preserve fertility, hCG, clomiphene and the combination raised testosterone similarly, and 28 men who switched from TRT to hCG alone kept similar testosterone on average. Full sperm production may also need FSH. [83], [84], [85]

Are aromatase inhibitors used for fertility?

Sometimes, off-label, with limited evidence. Anastrozole raised average sperm concentration from 5.5 to 15.6 million per mL in 25 men with low counts, without a comparison group. In a 2026 randomized trial of 296 men with severe sperm-production failure, letrozole added to vitamins C and E moved more men up a WHO sperm-count category than the vitamins alone (21 of 147, 14.3%, vs 8 of 149, 5.4%), but the other semen measures did not differ between the groups, and lower sex drive was more common (18 vs 8 men). The EAU advises against routine use for unexplained infertility, and a year of anastrozole lowered spine bone density in older men. [76], [77], [20], [86]

Can losing weight restore testosterone?

Often partly, when excess weight is the cause. In a meta-analysis, testosterone rose by about 2.9 nmol/L (84 ng/dL) after a low-calorie diet and 8.7 nmol/L (251 ng/dL) after weight-loss surgery, with bigger losses giving bigger rises. A 2026 review found GLP-1 weight-loss medicines raised testosterone in men with obesity or diabetes while keeping LH and FSH working, unlike TRT. See TRT and GLP-1 medicines. [78], [87]

Should you bank sperm before TRT?

If children might matter to you, it is the most dependable back-up, though frozen sperm cannot guarantee a pregnancy. The Endocrine Society suggests considering sperm banking when fertility plans are uncertain, and the American Society for Reproductive Medicine (ASRM) calls freezing sperm from the semen an established method. No guideline says every man starting TRT must bank sperm. [2], [13]

• How many samples. ASRM and the US infertility guideline advise banking several samples where possible, because each frozen sample is limited and IUI needs more moving sperm than IVF. [13], [7]
• What freezing does. Freezing and thawing loses some moving sperm: in one study, 58% of the moving sperm in samples from men with poorer fertility kept moving after thawing, against 68% in donor samples. [88]
• How long it keeps. Frozen sperm has produced births after about 40 years of storage. In the UK, the law allows storage for up to 55 years if consent is renewed every 10 years, since July 1, 2022. [89], [90]
• How often it is used. Most men never need their banked sperm: in studies of men who banked before cancer treatment, fewer than 10% later used it. [7]
• Cost and funding. There is no official price; clinics set their own fees for freezing and yearly storage, so ask for both in writing. One NHS trust says its funded banking is only for cancer patients, so ask your local fertility service whether banking before TRT is funded. Checked September 2026. [91]

Does TRT shrink your testicles, and do they come back?

Usually yes to both. Testicle volume fell by about 19% in 4 months in healthy men given weekly injections, and returned to normal after stopping. hCG keeps the testicle's own testosterone production going, which is why many men use it for size, but size and semen volume do not show whether sperm are being made; only a semen analysis does. [31], [11]

Do supplements help sperm on TRT?

No supplement has been shown to protect sperm on TRT, and the best trials in men with fertility problems found none that improved live births. In a trial of 2,370 couples, folic acid and zinc did not improve semen quality or live births (404 of 1,185 couples, 34%, vs 416 of 1,185, 35%, on placebo). In a trial of 174 men, an antioxidant blend did not improve semen results, and live births were 15% vs 24% on placebo, a difference that could be chance. The US infertility guideline calls supplements of questionable value. See zinc and CoQ10. [92], [93], [7]

Where can you get hCG or FSH?

Only on prescription, and availability differs by country (checked September 2026). In the US, approved hCG products are available and no shortage is listed, but pharmacies cannot compound it. In the UK, the main brands are discontinued and supply relies on unlicensed imports. Canada has two marketed hCG products, and Australia subsidises recombinant hCG for some men through specialists. See legal status. [53], [94], [58], [56], [60]

What if you used anabolic steroids?

Recovery is usually slower. In the HAARLEM study of 100 amateur athletes, 34% of those assessed still had a total sperm count below 40 million a year after their cycle began, and in another study sperm output took about 14 months on average to recover after stopping. See TRT vs steroids. [49], [95]

What do people on TRT report about fertility?

Public forums are full of men facing the same decision: stay on TRT, stop and wait, or try hCG or tablets. The threads below are public Reddit discussions from 2025 and 2026, read with their replies; they show what people experience, not how often it happens.

What does a semen analysis on TRT usually show?

Often no sperm at all, sometimes quickly. One man whose motile count was 194 million before starting had none after 9 weeks on 150 mg a week, with hCG added only in the last 2 weeks; he had frozen sperm beforehand and decided to stop. [96] Another man had no sperm after about 15 months on 75 then 100 mg a week, with LH and FSH undetectable. [97] A man on TRT for 5 years without hCG found no sperm and asked whether he could rely on that as contraception; most replies warned that one zero result is not birth control. [98] Another man's partner became pregnant after he had been on 120 mg a week for 10 months without hCG, and a home test later showed sperm. [99]

How long did recovery take after stopping?

Anywhere from weeks to many months. One man stopped after about 8 years of non-prescribed testosterone at 500 mg a week, felt rough for 6 months, and had normal semen results around month 10; a pregnancy followed, while replies included men with zero sperm months after stopping. [100] Another, about 2 months off after 2.5 years, had 62 million per mL but low motility, having also lost 70 lb and changed an epilepsy medicine in the same period. [101]

Others were slower. After 6 years of TRT without hCG, one man still had no sperm after about 3 months of hCG with hMG added. [102] Another, after more than 4 years of testosterone and other steroids, saw home sperm tests rise from under 2 million to 6 million over 3 months on hCG, hMG and briefly clomiphene, and his partner's test was positive 102 days after his last injection. [103]

What about staying on TRT with hCG?

Some couples conceived and some men saw no change. One man with a near-absent count added hCG 250 IU twice a week to testosterone 120 mg a week, and a pregnancy followed about 4 months later, though hCG made him tired and irritable. [104] Another, on 180 mg a week with hCG 500 IU twice a week, reported a normal semen analysis after 3 months of hCG; he later described three very early pregnancy losses (chemical pregnancies) and a missed miscarriage whose cause had not been found. [105] A third saw no improvement in his count after 8 weeks of hCG 3,000 IU a week on testosterone 100 mg a week and was about to add FSH. [106]

What do men say about hCG's side effects, cost and supply?

Unwanted effects come up in most hCG threads: tiredness with worse libido and erections on 300 IU three times a week, and bloating, acne, mood swings and weaker erections after 1,000 IU a week was added without changing the testosterone dose. [107], [108] Costs vary: one pharmacy quoted $750 a month for hCG alone after a urologist suggested it, and another about $208 for three months that insurance would not cover. [109], [110] In the UK, one man went without hCG for several months because of a supply problem. [111]

Several threads show why size and volume mislead. After 6 weeks of hCG, one man's testicles grew from 6 to 8.5 mL on ultrasound, but he had no semen result yet, and replies pointed out that size does not show sperm. Another saw more semen volume on hCG, and replies urged a semen analysis. [112], [113]

What happened with tablets instead?

One man whose count fell on TRT was switched by his urologist to clomiphene 25 mg every other day; over 3 to 4 years his count recovered, but libido and erections stayed poor. [109] Another, after 3.5 years of TRT and more than 8 months of trying while tapering with hCG, reported positive home pregnancy tests 5 weeks after starting enclomiphene 25 mg a day; he had no semen analysis to show what changed. [114]

What do men wish they had done before starting?

Test and bank first. A man with a baseline analysis and six frozen vials before TRT planned repeat analyses once on hCG, with IUI and IVF as a back-up. [115] A man on TRT for 2 years had a fertility specialist's office ask him to stop before his first visit, and wished he had frozen sperm first. [116] Others planned a semen analysis and possible freezing before deciding. [117]

How can you judge a fertility story?

Ask: Was there a semen analysis before TRT? Was the result a lab analysis or a home test? What testosterone was used, how much and for how long, and were other steroids involved? Was hCG, FSH or a tablet used, and for how long before the result? Were there fertility problems in either partner, and was the pregnancy confirmed? And what did the next test show?

These selected discussions show what people experience and the questions research has not answered. They are not a survey of all men on TRT, a success rate or a substitute for the studies above.

What should you track?

A semen analysis is the only test that shows sperm production, though on its own it cannot say whether a couple will conceive; hormone tests show whether the signals are working. Use this summary to prepare questions for your clinician; it is not a personal testing plan. [2], [17]

[2], [17], [46], [6], [44]

Because new sperm take about 64 days to reach the semen, a change in treatment shows up on a semen analysis about 2–3 months later, so tests taken sooner can mislead in either direction. The TRT blood work guide covers when to draw each hormone test. [29], [30]

Common questions about TRT and fertility

Will TRT make me infertile?

It very likely lowers your sperm count while you take it, often to zero, but for most men the effect reverses after stopping: in contraception trials, 90% were back to 20 million per mL within 12 months. Some men recover slowly or incompletely, especially after years of use. [4], [9], [7] See the research.

How long after stopping TRT does sperm come back?

Usually 3 to 12 months, sometimes longer. The median was 3.4 months in pooled contraception trials and about 4.5 to 8.5 months in small clinic series of men who had used prescribed testosterone, and some still had no sperm after that. [9], [42], [10], [43] See recovery.

If I've been on TRT for 5 or more years, can I still recover fertility?

Many men do, but it tends to take longer. In the Kohn series of men treated with hCG and a SERM after a median 2 years of testosterone, each extra year of use lowered the chance of recovery within a year by about 3 percentage points. Specialist treatment and, if needed, sperm retrieval for IVF are options when sperm does not return. [46], [7] See what guidelines do.

Does hCG guarantee fertility on TRT?

No. hCG keeps testosterone production going inside the testicle, but no trial has tested whether it preserves sperm or pregnancy rates, a case report describes almost no sperm despite hCG, and the US infertility guideline says the evidence is too limited to recommend it. [11], [70], [71], [7] See staying on TRT.

Does normal testosterone mean normal fertility?

No. On TRT your blood testosterone can be normal or high while testosterone inside the testicle, and with it sperm production, is switched off. Only a semen analysis shows whether sperm are being made. [11], [17] See how it happens.

Is TRT a form of birth control?

No. Pregnancies occurred even in closely monitored contraception trials, and men on TRT do not know whether their count is zero or just low. The Society for Endocrinology says contraception should always be discussed. [48], [33], [17] See contraception.

Should young men worry about TRT and fertility?

Yes, if they may want children. Guidelines say fertility plans should be discussed before starting, and banking sperm first keeps a back-up option. In the contraception trials, older men actually recovered faster, so youth does not guarantee a quick return. [6], [2], [9] See sperm banking.

Glossary

Plain explanations of the medical, lab and research terms used in this guide. Underlined terms in the text link here.

Aromatase inhibitor

A medicine, such as anastrozole or letrozole, that blocks the enzyme that turns testosterone into estradiol. It is used off-label in some men with fertility problems.

Azoospermia

No sperm at all in a semen sample.

Cohort study (records study)

A study that follows a group of people, or looks back at their records, without assigning treatments. It can show links but not prove that one thing caused another.

Controlled trial

A study that compares people who receive a treatment with a similar group who do not, often receiving a placebo instead. Randomly assigning people to each group makes the comparison fairer.

Sperm banking (cryopreservation)

Freezing semen samples in liquid nitrogen so they can be used later for IUI or IVF. Some moving sperm are lost when a sample is thawed.

Estradiol

The main form of estrogen. In men it is made mostly from testosterone, so it rises when testosterone rises.

FSH (follicle-stimulating hormone)

A pituitary hormone that acts on the Sertoli cells in the testicles. It is needed for sperm production, and testosterone therapy lowers it.

GnRH (gonadotropin-releasing hormone)

The brain signal that tells the pituitary to release LH and FSH. Gonadorelin is a medicine that copies it.

Clinical guideline

Recommendations written by a medical society or health system, based on its review of the evidence and expert judgment. Different guidelines can reach different conclusions.

hCG (human chorionic gonadotropin)

A hormone medicine that acts like LH on the testicles, so they keep making testosterone even when the pituitary signal is switched off. It is approved for men with low LH and FSH.

Secondary (hypogonadotropic) hypogonadism

Low testosterone because the brain and pituitary send too little LH and FSH to the testicles. It can be present from birth or start later. Hormone treatment can often start sperm production.

hMG (human menopausal gonadotropin)

A medicine containing FSH and LH activity, purified from urine. It is added to hCG when sperm production needs FSH.

HPG axis

The hormone chain from the hypothalamus in the brain to the pituitary gland to the gonads (testicles). Testosterone from outside the body turns it down.

IUI (intrauterine insemination)

A fertility treatment that places prepared sperm directly into the womb. It usually needs a total motile count of at least 5–10 million in the sample.

IVF and ICSI

In vitro fertilization joins eggs and sperm in a laboratory. With ICSI (intracytoplasmic sperm injection), one sperm is injected into each egg, so very few sperm are needed.

Leydig cells

Cells in the spaces between the testicle's tubules that make testosterone when LH or hCG reaches them.

LH (luteinizing hormone)

A pituitary hormone that tells the testicles to make testosterone. Testosterone therapy switches it off.

Micro-TESE

Microdissection testicular sperm extraction: a surgery that searches the testicle under a microscope for areas making sperm, for use in IVF with ICSI.

Off-label

Use of an approved medicine for a condition, group or dose its label does not cover, such as clomiphene in men.

Oligozoospermia

A low sperm count. Severe oligozoospermia means very few sperm; contraception trials used below 3 million per mL.

Pituitary gland

A pea-sized gland under the brain that releases LH, FSH and other hormones on instructions from the hypothalamus.

Placebo

A dummy treatment with no active ingredient, used as a comparison in studies.

Primary hypogonadism

Low testosterone because the testicles themselves do not work well, even though the pituitary sends plenty of LH and FSH. Hormone treatment usually cannot restart sperm production.

Semen analysis

A lab test of a semen sample that measures volume, sperm concentration, total number, movement (motility) and shape. It is the only direct test of sperm production.

SERM (selective estrogen receptor modulator)

A tablet, such as clomiphene, enclomiphene or tamoxifen, that blocks estrogen's feedback in the brain so the pituitary releases more LH and FSH.

Sertoli cells

Cells lining the testicle's tubules that support developing sperm. They respond to FSH and to the high testosterone level inside the testicle.

Spermatogenesis

The process of making sperm inside the testicles. It takes about 64 days from start to finish.

Total motile count

The number of moving sperm in a whole semen sample: volume times concentration times the share that move. Fertility clinics use it to choose between IUI and IVF.

TRT (testosterone replacement therapy)

Prescribed testosterone, by injection, gel or other forms, for men with low testosterone. It switches off the brain's LH and FSH signals.

WADA

The World Anti-Doping Agency, which publishes the list of substances banned in sport. Testosterone is banned at all times, and hCG in men.

How this guide was researched

This guide is built from a thorough review of the sources cited throughout it: clinical guidelines and position statements from medical societies and health systems, product labels from several countries, male contraception trials, studies of men on prescribed testosterone, fertility treatment series and regulatory documents. We also reviewed public online forums where men on TRT describe their own fertility experiences.

The guide cites 117 sources, including 46 studies and reports in people, 15 clinical guidelines, position statements and committee opinions, and 22 public community discussions. Each type of source answers a different question. Guidelines and labels show what clinicians are told to do. Trials and studies show what was measured. Personal accounts show what individual people experienced. Every numbered citation links to its entry below, labeled by source type.

How this guide was made

Research and drafting were AI-assisted. Every cited source was checked against the original, and the guide was reviewed and edited by Doserly before publication. It has not had an independent clinical review, and Doserly does not currently have medical reviewers. Doserly makes a medication and health-tracking app and runs Doserly Academy, both of which are promoted in this guide. Read our editorial policy for how guides are researched, updated and corrected.

This guide is for educational purposes. It summarizes what the reviewed sources report so the research is easier to understand; it is not medical advice. For a deeper dive, or to check any point for yourself, go straight to the cited sources.

Explore the sources