TRT and Fertility: How to Preserve Sperm Production on Testosterone Therapy
This is one of the most important conversations I have with patients — and unfortunately, one of the most frequently botched by prescribers who should know better. If you're considering testosterone replacement therapy, already on it, or worried about the impact on your fertility, this guide gives you the complete picture: what happens, why, and what we can do about it.
I'm Mr Ollandini, a consultant urological surgeon specialising in andrology and male fertility. Fertility preservation during TRT is a core part of my practice. I've seen the consequences of poorly managed hormonal therapy — men referred to me by fertility clinics with zero sperm and a partner running out of time. These situations are almost always preventable. The conversation just needs to happen at the right time.
Already on TRT without fertility protection?
If you're currently on testosterone and haven't discussed fertility with your prescriber, don't panic — but do act. Recovery is possible in the vast majority of cases. The sooner you get specialist input, the more options you have. Get in touch now.
The short version
Standard TRT is effectively a male contraceptive. It suppresses the brain signals (LH and FSH) that drive sperm production, often causing severe oligospermia or complete azoospermia. This is the expected response, not a rare side effect. But fertility-preserving protocols exist — and they work. The key: the conversation must happen before treatment starts. If you're already on TRT, recovery is possible in over 90% of men, though it can take 6 to 18 months.
On this page
Why TRT is effectively a male contraceptive
Let me be direct: standard testosterone replacement therapy suppresses sperm production. This is not a risk. It is not a rare side effect. It is the predictable, expected physiological consequence of giving a man exogenous testosterone. The WHO studied this extensively in the 1990s as a potential male contraceptive — because it works.
The numbers are sobering. Within 3 to 6 months of starting TRT, the majority of men will develop severe oligospermia (very low sperm count) or complete azoospermia (no sperm at all). One large meta-analysis found that roughly 65% of men on testosterone-based regimens developed azoospermia. The suppression is dose-dependent and delivery-method-dependent, but no form of standard TRT is "fertility safe" without additional precautions.
Despite this, an alarming proportion of men are started on TRT without any discussion of fertility. A 2019 survey of US urologists found that 25% still did not discuss fertility implications before initiating TRT in men of reproductive age. Online testosterone clinics and non-specialist prescribers are often worse. I've lost count of the number of men who've told me: "Nobody mentioned this."
This is what I mean when I say the conversation needs to happen first.
The 2026 clinical standard
Every major guideline body — BSSM, EAU, AUA, Endocrine Society — now mandates that fertility status and reproductive intentions must be discussed with every man of reproductive age before initiating TRT. At GGO Med, this is a non-negotiable part of every first consultation. If you haven't been asked about your fertility plans, your prescriber has not met the standard of care.
The HPG axis — understanding the mechanism
Understanding why TRT suppresses fertility — even at "replacement" doses — helps you understand why the solutions work. If the biology doesn't interest you, skip to the fertility-preserving toolkit. But for many of my patients, understanding the mechanism makes the treatment plan feel less arbitrary and more logical.
How the hormonal axis controls sperm production
The fertility-preserving toolkit
The good news: we have effective tools to maintain or restore fertility in men who need testosterone therapy. The approach depends on your timeline, your diagnosis, and whether you've already started TRT.
How it works: hCG is an LH analogue — it mimics the action of LH by binding to the same receptors on Leydig cells. When administered alongside TRT, it maintains intratesticular testosterone at levels sufficient to support spermatogenesis, even though the brain's own LH production is suppressed.
Evidence: A landmark 2025 study from Baylor College of Medicine (Stocks et al., Fertility and Sterility) demonstrated that 74% of men with TRT-related infertility showed improved sperm concentrations with hCG/FSH combination therapy. Crucially, this improvement occurred equally in men who continued TRT during treatment and those who stopped — challenging the previous assumption that exogenous testosterone must always be discontinued.
Dosing (maintenance during TRT): 500 to 1,000 IU subcutaneously, 2 to 3 times per week. This is sufficient to maintain intratesticular testosterone at a level that preserves spermatogenesis in most men. Higher doses (1,500 IU weekly) are used to prevent testicular atrophy in men not actively trying to conceive.
Dosing (fertility recovery): 1,500 to 3,000 IU subcutaneously, every other day. This aggressive protocol is used when fertility has already been compromised and recovery is needed urgently.
Side effects: Generally well tolerated. Potential for breast tenderness (oestradiol increase via aromatisation of the additional intratesticular testosterone), water retention, and mood fluctuation. Monitoring oestradiol levels is important. In rare cases, an aromatase inhibitor may be needed as an adjunct.
Availability: hCG is licensed in the UK (Pregnyl, Ovitrelle). It requires a prescription and is administered by subcutaneous injection — most patients learn self-injection in minutes.
How it works: Clomiphene is a selective oestrogen receptor modulator (SERM). It blocks oestrogen receptors in the hypothalamus, tricking the brain into thinking oestrogen levels are low. The brain responds by increasing GnRH output, which drives up LH and FSH — stimulating both testosterone production and spermatogenesis naturally.
Key advantage: Because clomiphene stimulates endogenous testosterone production rather than replacing it, the testes produce their own testosterone, maintaining the intratesticular concentrations needed for sperm production. It's the only approach that raises testosterone and preserves (or improves) fertility simultaneously.
Dosing: 25 to 50 mg daily or every other day. It can be used as monotherapy (instead of TRT) for men with secondary hypogonadism, or as an adjunct to hCG during fertility recovery protocols.
Limitations: It doesn't work for primary hypogonadism (the testes can't respond regardless of how much LH and FSH they receive). Side effects include visual disturbances (rare but important — typically reversible), mood changes, and headaches. It's used off-label in men (licensed for female ovulation induction). Not all men achieve adequate testosterone levels on clomiphene alone.
Recovery evidence: In a large case series, combination therapy with hCG (3,000 IU every other day) plus clomiphene produced return of spermatogenesis in 96% of men with TRT-induced azoospermia, at an average of 4.6 months — significantly faster than spontaneous recovery.
What is it: Enclomiphene is the purified active trans-isomer of clomiphene citrate. Standard clomiphene is a racemic mixture of two isomers: enclomiphene (the one that works on the hypothalamus) and zuclomiphene (which has oestrogenic activity and is responsible for many of clomiphene's side effects).
Why it matters: By removing the zuclomiphene component, enclomiphene provides the same hypothalamic stimulation with fewer oestrogenic side effects — less mood disruption, fewer visual disturbances, and more predictable dose-response.
Clinical position: Enclomiphene is rapidly becoming the preferred first-line option for younger men with secondary hypogonadism who want to maintain fertility. It raises endogenous testosterone, preserves spermatogenesis, and avoids the contraceptive effect of exogenous testosterone entirely.
Availability: Currently available in the UK through specialist prescription. Regulatory status continues to evolve — it's worth discussing current access with your prescriber.
When it's needed: FSH is added to the protocol when hCG alone hasn't restored adequate sperm production. This typically occurs in men with prolonged TRT-induced suppression where the Sertoli cells need direct FSH stimulation to re-engage spermatogenesis.
Dosing: 75 IU subcutaneously, 3 times per week, typically added to hCG. The Baylor 2025 protocol (hCG 3,000 IU + FSH 75 IU, three times weekly) achieved 74% improvement in sperm concentrations across their cohort.
Cost consideration: rFSH (Gonal-f) is significantly more expensive than hCG or clomiphene. I reserve it for cases where simpler protocols haven't worked, or where time pressure (partner's age, IVF cycle timeline) demands the most aggressive approach available.
Protocols by timeline — matching treatment to your plans
The right approach depends entirely on when you want to conceive. I tailor the protocol to your specific timeline, and I reassess regularly as plans evolve.
Step 1: Stop all exogenous testosterone immediately. There is no half-measure here — you cannot conceive while your HPG axis is suppressed by ongoing TRT.
Step 2: Start aggressive recovery protocol. High-dose hCG — typically 3,000 IU subcutaneously every other day — combined with clomiphene citrate 25 to 50 mg daily. This simultaneously restores intratesticular testosterone and reactivates the pituitary's own gonadotropin output.
Step 3: Semen analysis every 8 weeks to track recovery. First sperm typically appear at 2 to 4 months. Full recovery to baseline may take 6 to 12 months.
Step 4: If FSH remains suppressed and semen parameters are not improving at the 3-month mark, add rFSH 75 IU three times weekly to directly support Sertoli cell function.
Step 5: Concurrent partner assessment. While you're recovering, your partner should also be assessed — there's no point waiting 6 months for your sperm to return only to discover a concurrent female factor that delays things further.
What to expect: You will likely feel worse during the recovery period — fatigue, mood dips, reduced libido — as your endogenous testosterone production restarts. This is temporary. I manage expectations carefully and offer symptomatic support where appropriate.
Option A — Continue TRT with hCG co-therapy: TRT can potentially continue, but must be co-administered with hCG (500 to 1,000 IU subcutaneously, 2 to 3 times per week) to maintain intratesticular testosterone above the critical threshold for spermatogenesis. Clomiphene may be added as an adjunct.
Option B — Switch to SERMs: For men with secondary hypogonadism, transitioning from TRT to enclomiphene or clomiphene alone may maintain adequate testosterone levels while preserving or restoring spermatogenesis. This avoids the HPG suppression entirely but may not achieve the same symptomatic relief as exogenous testosterone in all men.
Monitoring: Semen analysis every 8 to 12 weeks. Hormonal levels (testosterone, LH, FSH, oestradiol) at each check. Close monitoring is non-negotiable — the window is tight, and adjustments may be needed.
Maintenance protocol: For men who need long-term TRT but want to preserve the option of fatherhood, I maintain hCG alongside testosterone from the outset — typically 500 to 1,000 IU twice weekly. This prevents testicular atrophy and fibrosis, which makes future recovery much easier and faster.
Periodic reset: An alternative strategy is a periodic "hCG reset" — 4 weeks off TRT with intensive hCG (3,000 IU every other day) every 6 months — to confirm the testes can still respond and spermatogenesis can restart. This provides ongoing reassurance without committing to continuous co-therapy.
Sperm banking: Always discussed before starting TRT. It's an insurance policy — straightforward, relatively inexpensive, and removes the time pressure if plans change unexpectedly. See the sperm banking section below.
Not sure which approach fits your situation?
The right protocol depends on your diagnosis, your partner's situation, your timeline, and your priorities. This is exactly the kind of conversation I have every week. Book a consultation and we'll map it out together.
Sperm banking — your insurance policy
I recommend discussing sperm banking with every man of reproductive age before starting TRT. Not because I think things will go wrong — but because life is unpredictable, and having frozen sperm removes the time pressure entirely.
You provide one or more semen samples at a licensed fertility clinic. The samples are analysed, processed, and frozen using controlled-rate cryopreservation in liquid nitrogen at minus 196°C. At these temperatures, sperm can be stored indefinitely — there are documented pregnancies from sperm stored for over 20 years.
The process itself takes about an hour per visit. Most men provide 2 to 3 samples over 1 to 2 weeks to ensure adequate backup. The samples are then available for future use in intrauterine insemination (IUI), IVF, or ICSI depending on sperm quality and your partner's situation.
Initial consultation, analysis, and freezing typically costs £300 to £600 in London. Annual storage fees are around £150 to £350 per year depending on the clinic. Some clinics offer multi-year storage packages at reduced rates.
I can refer you to licensed clinics that I work with regularly. The turnaround is usually within a week or two — which is why I recommend doing this before you start TRT, not after you've already decided you want to.
Men with primary hypogonadism (where recovery after stopping TRT is less certain), men starting TRT before age 35, men with partners over 35 (where any delay in conception has more impact), men with pre-existing borderline semen parameters, and men starting long-acting preparations like Nebido (where suppression is more complete and recovery potentially slower). If any of these apply to you, banking isn't optional — it's good medicine.
Recovery after stopping TRT — realistic timelines
The question I get asked most: "If I stop testosterone, will my sperm come back?"
In the vast majority of cases, yes. But "majority" is not "all," and the timeline varies considerably.
The recovery data
A large meta-analysis of men who stopped testosterone-based contraceptive regimens found that 67% recovered sperm concentrations above 20 million/mL within 6 months. By 12 months, 90% had recovered. By 16 months, 96%. By 24 months, 100% in the studied cohorts.
However, these were primarily research subjects on time-limited protocols with normal baseline fertility. Real-world recovery — in men who may have been on TRT for years, who may have had suboptimal baseline counts, who may be older — can be less predictable. Active recovery protocols (hCG + clomiphene) significantly accelerate the timeline compared to spontaneous recovery after simply stopping.
Duration of TRT: Longer suppression generally means slower recovery. Men on TRT for under 6 months typically recover faster than those on multi-year treatment.
Age: Younger men (under 40) have more responsive HPG axes and tend to recover faster.
Delivery method: Long-acting preparations (Nebido) cause more complete and prolonged suppression than gels. Recovery may take longer.
Baseline fertility: Men who had normal semen parameters before TRT have a better recovery trajectory than those who started with borderline counts. This is one reason baseline semen analysis is important before starting treatment.
Use of hCG during TRT: Men who used concurrent hCG during TRT typically recover faster than those who were on testosterone monotherapy — the testes have been kept "warm" rather than allowed to atrophy.
Individual variation: Some men recover within weeks. Others take 18 months. Individual biology, genetics, and as-yet-unidentified factors all play a role. There's no way to guarantee your specific timeline — only to give you the best possible chance with an evidence-based protocol.
What if recovery doesn't happen?
When to involve a reproductive medicine specialist
I manage the majority of fertility-preservation protocols myself — it's a core part of my andrology practice. But there are specific situations where I involve a dedicated reproductive medicine specialist or fertility clinic:
- When the female partner has known fertility factors that affect the timeline or approach
- When assisted reproduction (IVF, ICSI) is likely to be needed regardless of sperm recovery
- When recovery after TRT cessation plateaus despite aggressive medical therapy
- When micro-TESE or other surgical sperm retrieval is being considered
- When the couple has been trying to conceive for over 12 months without success (even with recovered sperm parameters)
- When the female partner's age creates time pressure that requires parallel rather than sequential management
I work within a network of trusted fertility specialists and reproductive endocrinologists. If your case needs coordinated care, I'll facilitate the referral and stay involved — not hand you off.
The ethics — balancing quality of life with fertility
This is the part that doesn't get discussed enough. The clinical textbooks make it sound straightforward: assess fertility intent, choose protocol, follow algorithm. In reality, it's rarely that clean.
I regularly see men in their thirties who are genuinely suffering from testosterone deficiency — fatigue, depression, lost libido, relationship strain — who also want children in the next few years. The deficiency is real, the suffering is real, and the fertility concern is real. The three don't resolve neatly.
Starting TRT provides rapid symptomatic relief but introduces fertility risk. Deferring TRT preserves fertility but leaves the man suffering. Clomiphene or enclomiphene may split the difference but don't always achieve the same symptomatic improvement as exogenous testosterone. hCG co-therapy adds complexity, cost, and injection burden.
There is no universally right answer. My role is to lay out the options honestly — with realistic probabilities, timelines, and trade-offs — and then support whichever decision the man and his partner make. The worst outcome is the one that happens by default because nobody had the conversation.
First principle — do no harm but treat anyhow
Knowledge check
Quick check: TRT and fertility
A 34-year-old man with confirmed secondary hypogonadism wants to start testosterone therapy. He and his partner are planning to start a family within the next year. What's the most appropriate approach?
Frequently asked questions
Suppression begins within weeks, but complete azoospermia typically takes 3 to 6 months. The speed depends on the delivery method (long-acting injectables suppress faster and more completely than gels), the dose, and individual sensitivity. Some men maintain low-level spermatogenesis even on TRT — but this is unreliable and cannot be counted on for contraception or for fertility.
No — and this is important. Although TRT suppresses sperm production dramatically, the suppression is not reliable enough for contraception. The WHO contraceptive trials showed that roughly 5% of men maintained sperm production above the azoospermic threshold even on full-dose testosterone. You should not rely on TRT as your sole method of contraception. Use standard contraception alongside it.
Yes. Long-term concurrent hCG is the standard approach for men of reproductive age on TRT who want to preserve fertility potential. The doses used for maintenance (500 to 1,000 IU, 2 to 3 times weekly) are generally well tolerated. The main considerations are: cost (hCG is not free, though it's far cheaper than fertility treatment later), injection burden (additional 2 to 3 subcutaneous injections per week), and monitoring (periodic semen analysis and hormone levels to confirm the protocol is working). For most men, these are manageable trade-offs.
It's not too late. Recovery is possible in the vast majority of men, even after prolonged suppression. The meta-analysis data shows that with sufficient time and appropriate medical therapy, spermatogenesis recovers to baseline in over 90% of men. Longer TRT duration may mean slower recovery — months rather than weeks — but the prognosis is generally good. What matters now is starting a structured recovery protocol with specialist oversight, not dwelling on what should have been done differently.
If you've recovered sperm production (either naturally or with hCG/FSH), the sperm are functionally normal — TRT does not cause permanent DNA damage or structural sperm defects. IVF and ICSI success rates are determined by sperm quality at the time of the procedure, not by your history of TRT use. The key is timing: ensure your recovery protocol has produced adequate sperm before the IVF cycle. If you've banked sperm pre-TRT, that's even simpler — banked samples are immediately available for ICSI.
References and further reading
- Stocks BT, et al. Optimal restoration of spermatogenesis after testosterone therapy using human chorionic gonadotropin and follicle-stimulating hormone. Fertil Steril. 2025;123(4):607-615.
- Wenker EP, et al. The use of HCG-based combination therapy for recovery of spermatogenesis after testosterone use. J Sex Med. 2015;12(6):1334-1337.
- Liu PY, et al. Rate, extent, and modifiers of spermatogenic recovery after hormonal male contraception: an integrated analysis. Lancet. 2006;367(9520):1412-1420.
- Coviello AD, et al. Low-dose human chorionic gonadotropin maintains intratesticular testosterone in normal men with testosterone-induced gonadotropin suppression. J Clin Endocrinol Metab. 2005;90(5):2595-2602.
- Samplaski MK, et al. Recovery of spermatogenesis following testosterone replacement therapy or anabolic-androgenic steroid use. Asian J Androl. 2015;17(1):5-9.
- British Society for Sexual Medicine (BSSM). Guidelines on the Management of Sexual Problems in Men: The Role of Androgens. 2023.
- European Association of Urology (EAU). Guidelines on Male Hypogonadism. 2024.
- American Urological Association (AUA). Evaluation and Management of Testosterone Deficiency. 2024 update.
- Bhasin S, et al. Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2018;103(5):1715-1744.
- Patel AS, et al. Preserving spermatogenesis in testosterone deficiency: innovations in replacement and stimulatory therapies. Transl Androl Urol. 2025;14(12):2668-2680.
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