TRT and Fertility in NYC: How Testosterone Shots Affect Sperm and How to Protect Your Options

Most men who ask about testosterone shots are thinking about energy, libido, body composition, and mood. Very few walk in thinking about sperm. Yet TRT and fertility are tightly linked, and the link runs in a direction that surprises a lot of patients: the testosterone you inject can shut down the testosterone your testicles make, and with it the signal your body uses to produce sperm. For a man who wants children now or later, that is the single most important fact to understand before the first injection.

This guide explains what testosterone shots do, why they lower sperm production, how often that reverses, and what the alternatives are for men who want to treat low testosterone without closing the door on fatherhood. It also includes a practical decision table built around a simple question: are you planning a family in the next one, three, or five years? Your answer changes the plan.

Nothing here replaces an individual evaluation. The right plan depends on your labs, your age, your partner's age, and your timeline.

What Is a TRT Injection, and What Do Testosterone Shots Do for Men?

TRT stands for testosterone replacement therapy. A TRT injection is a dose of a testosterone ester, most commonly testosterone cypionate or testosterone enanthate in the United States, given into a muscle or under the skin on a regular schedule, often weekly or every one to two weeks. The ester slows release so blood levels rise over a day or two and drift down before the next dose.

So what do testosterone shots do? In a man with genuinely low testosterone and matching symptoms, restoring levels to a normal range can improve sexual desire, erectile function in some men, energy, mood, lean muscle mass, and bone density. Benefits for fatigue and mood are real for some men and modest for others. Our earlier piece on what to expect from testosterone shots walks through the typical timeline of how men feel in the first weeks and months.

What testosterone shots do not do is restore your own production. They replace it. That distinction is the whole story when it comes to fertility, and it explains most of the side effects of testosterone shots that men worry about later: smaller testicles, lower sperm counts, and a period of low testosterone if they stop abruptly.

How the Body Makes Testosterone and Sperm

To understand why testosterone injections affect fertility, it helps to see the control loop. The system is often called the hypothalamic, pituitary, gonadal axis, or HPG axis.

1. The hypothalamus in the brain releases gonadotropin releasing hormone (GnRH) in pulses.
2. GnRH tells the pituitary gland to release two hormones: luteinizing hormone (LH) and follicle stimulating hormone (FSH).
3. LH travels to the testicles and tells the Leydig cells to make testosterone.
4. FSH acts on the Sertoli cells, which nurse developing sperm.
5. Sperm production depends on both FSH and a very high concentration of testosterone inside the testicle itself, called intratesticular testosterone.

That last point is the key. The testosterone level inside the testicle is many times higher than the level in your blood. Sperm production needs that concentrated local supply. Blood testosterone, even at a healthy level, cannot substitute for it.

The brain also watches blood testosterone and estradiol. When those levels are high, the hypothalamus and pituitary dial down GnRH, LH, and FSH. This is ordinary negative feedback, the same principle as a thermostat.

Why Exogenous Testosterone Lowers Sperm Production

When you inject testosterone, your brain sees plenty of testosterone in the blood and responds by reducing LH and FSH, often to very low or undetectable levels. Without LH, the Leydig cells stop producing testosterone, and intratesticular testosterone falls sharply. Without FSH and intratesticular testosterone, the Sertoli cells cannot support sperm development.

The result is a drop in sperm count, sometimes a severe one. Many men on TRT develop oligospermia (low sperm count), and a substantial share develop azoospermia, meaning no sperm in the ejaculate at all. This effect is predictable enough that testosterone was studied for years as a potential male contraceptive. Some men still produce sperm, so TRT is not contraception, and it is not a guaranteed path to infertility either.

This applies to every form of exogenous testosterone, not just shots. Gels, creams, pellets, nasal products, and oral testosterone can all suppress LH and FSH. Injections and pellets tend to produce higher peaks and stronger suppression, but switching from a shot to a gel does not make testosterone fertility safe.

Testicular Shrinkage: A Visible Sign of Suppression

Roughly 80 to 90 percent of testicular volume is made up of the tubules where sperm are produced. When LH and FSH fall and sperm production slows, the testicles often become smaller and softer. Men usually notice this within a few months of starting TRT.

Testicular shrinkage is not dangerous in itself, but it is a visible marker that the internal machinery has quieted down. It is also one of the more common reasons men ask about adding hCG, which we will discuss below. If your testicles have changed in size on testosterone, that is worth raising during routine follow up in our men's health practice, especially if fertility is anywhere on your horizon.

What the AUA Guideline Says About Testosterone and Fertility

The American Urological Association's guideline on testosterone deficiency gives a direct recommendation: men who are interested in current or future fertility should not be prescribed testosterone therapy alone. The guideline also advises clinicians to discuss fertility before starting treatment and notes that exogenous testosterone suppresses sperm production.

The phrase "testosterone alone" matters. The guideline does not say men who want children can never have their low testosterone treated. It says testosterone by itself is the wrong tool for them, and that other approaches, including medications that work by raising the body's own production, are appropriate options to discuss.

In practice, this means a responsible testosterone consultation should always include a fertility conversation, even for a man who is single, even for a man who says he is "not sure yet." Not sure yet is precisely the situation where protecting your options makes the most sense.

Is It Reversible? Recovery Timelines After Stopping TRT

The reassuring news is that for most men, sperm production does recover after testosterone is stopped. The less reassuring news is that recovery takes time and is not guaranteed.

Sperm take roughly 64 to 74 days to develop from the earliest stage to mature cells, and then additional time to travel through the reproductive tract. So even once LH and FSH return, it takes about three months for that recovery to show up in a semen analysis.

Research on men who used testosterone for contraception found that most recovered sperm production within six to twelve months of stopping, with a large majority recovering by two years. Recovery tends to be slower and less certain when:

• testosterone was used for many years
• doses were high, including nonmedical anabolic steroid use
• the man is older
• there was an underlying testicular problem before TRT started
• baseline sperm counts were never measured, so it is unclear what "normal" was for him

A small number of men do not recover fully. Because we usually do not know in advance who those men will be, the safest plan for anyone who might want biological children is to measure first and, when appropriate, bank sperm before starting.

Stopping testosterone abruptly can also bring a rough stretch. While your own production restarts, testosterone levels may fall below where they started, and symptoms such as low energy, low libido, and low mood can return or worsen for weeks to months. A planned transition, sometimes using hCG or clomiphene, can shorten that dip.

These are general patterns, not promises. Your own timeline depends on the factors listed above.

Side Effects of Testosterone Shots Beyond Fertility

Since many men searching for TRT and fertility information are also asking about the side effects of testosterone shots in general, it is worth listing the main ones that we monitor:

• Reduced sperm production and testicular shrinkage, as described above.
• Higher hematocrit (thicker blood). Testosterone stimulates red blood cell production. Very high hematocrit can raise the risk of clotting problems, so we check it regularly and adjust the dose or frequency if it climbs.
• Acne and oily skin, more common with higher peaks after injections.
• Breast tenderness or enlargement, related to testosterone converting into estradiol.
• Fluid retention and blood pressure changes in some men.
• Worsening of untreated sleep apnea.
• Mood swings or irritability around peaks and troughs, which can sometimes be smoothed by more frequent, smaller doses.
• PSA changes, which is why prostate monitoring is part of routine follow up in age-appropriate men.

Many of these symptoms overlap with signs that testosterone is too high or too low, which is why we rely on labs, not guesses.

Fertility-Preserving Options for Men With Low Testosterone

If you have low testosterone and want to keep fertility, the goal shifts from replacing testosterone to encouraging your own body to make more of it. Several medications can do that. Each has trade-offs, and some uses are off-label, meaning the medication is FDA approved but not specifically for this purpose.

hCG (Human Chorionic Gonadotropin)

hCG acts like LH. It binds to the LH receptor on the Leydig cells and tells the testicles to produce testosterone directly, which raises intratesticular testosterone and helps sustain sperm production. hCG is used in two main ways:

• Alone, as an alternative to testosterone, in selected men with low testosterone who want to preserve fertility.
• Alongside low dose testosterone, to help maintain testicular size and intratesticular testosterone. Some studies suggest this combination can preserve sperm production in many men, but it is not as protective as avoiding testosterone altogether, and it does not replace FSH.

hCG is given by injection, usually two or three times per week. It can raise estradiol, so labs need monitoring. It has also attracted attention for unrelated uses; the debate over hCG diet plans is a separate topic, and the fertility use described here is the one with a clear physiological basis.

Clomiphene and Enclomiphene

Clomiphene citrate is a selective estrogen receptor modulator, or SERM. It blocks estrogen's feedback signal at the hypothalamus and pituitary, so the brain responds by releasing more LH and FSH. Both testosterone and sperm production can rise. Clomiphene is FDA approved for women's ovulation induction, so its use in men is off-label, but it has a long track record in male hormone and fertility care. It is taken by mouth.

Enclomiphene is one of the two components (isomers) of clomiphene and is thought to drive most of the testosterone-raising effect with fewer estrogen-like effects. It is not FDA approved, and its availability through compounding pharmacies has been restricted, so whether it is a practical option changes over time. Ask about current access rather than assuming.

Possible side effects of SERMs include mood changes, headaches, visual disturbances (rare but a reason to stop), and rises in estradiol. They work best in men whose testicles are capable of responding, which is one reason baseline labs matter.

Anastrozole in Selected Cases

Anastrozole is an aromatase inhibitor. It reduces the conversion of testosterone into estradiol, which can modestly raise testosterone and lower estradiol. It is used off-label in men, typically when the testosterone to estradiol ratio is unfavorable, often in men with higher body fat. It is not a first-line fertility treatment for most men, and over-suppressing estradiol can harm bone health, libido, and mood. It is a tool for specific lab patterns, not a routine add-on.

FSH and Specialist Care

For men who remain azoospermic after stopping testosterone, a male fertility specialist may add FSH preparations or recommend procedures such as testicular sperm extraction for use with IVF. These belong in reproductive urology, and we coordinate referrals when a man's situation calls for it.

Planning a Family in the Next 1, 3, or 5 Years: A Decision Table

This is the framework we find most useful in conversation. It does not depend on whether you are "sure" about children. It depends on your realistic timeline, and on the fact that a timeline can change.

Two practical notes on this table. First, your partner's timeline matters as much as yours. If your partner is in her late thirties, a one to two year recovery window after stopping TRT is a significant delay. Second, sperm banking is often far less burdensome than men expect: a few collections, frozen and stored, can provide options for intrauterine insemination or IVF later.

Pre-TRT Checklist: Questions to Answer Before Your First Injection

Use this self-assessment before starting any testosterone therapy. If you cannot check every box, pause and discuss it with your physician.

• I know whether I want biological children, and roughly when, or I have acknowledged that I am unsure.
• I have discussed my partner's age and fertility timeline, if relevant.
• My low testosterone has been confirmed on at least two separate morning blood tests, not one.
• I have had LH and FSH measured, so we know whether the problem is in the testicles or the brain.
• I have had a baseline semen analysis, or I have made a deliberate decision to skip it.
• I have considered sperm banking before starting.
• I understand that testosterone can shrink my testicles and lower or stop sperm production.
• I understand that recovery after stopping usually takes months and is not guaranteed.
• I have reviewed treatment options that raise my own testosterone (such as clomiphene or hCG).
• I have addressed reversible contributors: sleep apnea, excess weight, heavy alcohol use, opioid or other medications that suppress testosterone.
• I have disclosed any past anabolic steroid or testosterone use.
• I know my monitoring schedule (labs at baseline, a few months in, and periodically after).

Many of these items overlap with the broader hormone picture. Fatigue, poor sleep, and declining motivation can come from several systems at once, which we explore in our piece on the hidden signs your hormones are aging faster than you are.

What Labs to Ask For Before Starting Testosterone

Ask for these specifically. A single total testosterone level is not enough to plan treatment for a man who might want children.

A semen analysis measures volume, sperm concentration, total count, motility (movement), and morphology (shape). It costs relatively little compared with the information it provides, and it creates a baseline you cannot go back and collect later.

Who Should Check Before Starting TRT

Every man considering testosterone should have a fertility conversation, but some situations call for extra care:

• Men under 45, who are statistically more likely to want children in the future.
• Men in relationships where children are being discussed, even loosely.
• Men with a history of undescended testicles, varicocele, testicular injury, mumps orchitis, chemotherapy, or radiation, whose baseline sperm production may already be reduced.
• Men with prior anabolic steroid use, whose axis may already be suppressed.
• Men with secondary hypogonadism (low testosterone with low or normal LH and FSH), who are often good candidates for treatments that stimulate natural production.
• Men already on TRT who have changed their minds about children. This is common, and it is fixable in many cases with a structured plan rather than an abrupt stop.

There is a broader cultural conversation about men taking testosterone in midlife, which Dr. Bissoon has discussed publicly; the Financial Times piece on testosterone captures some of that debate.

If You Are Already on Testosterone and Want Children

If you are currently on TRT and now want to conceive, do not panic, and do not simply stop on your own. A typical approach looks like this:

1. Get a semen analysis now to see where you stand. Some men on TRT still have measurable sperm.
2. Plan the transition. Your physician may stop testosterone and start hCG, clomiphene, or both, to restart your own production and avoid a long symptomatic crash.
3. Recheck hormones in about 6 to 8 weeks, including LH, FSH, total testosterone, and estradiol.
4. Repeat semen analysis about every 3 months until counts recover.
5. Involve a male fertility specialist if there is no sperm after 6 to 12 months, or sooner if your partner's age makes time a priority.

TRT and Fertility in NYC: Practical Considerations

For many New Yorkers, the timeline question is especially pressing. People often start families later, careers are demanding, and men in their thirties and forties may come in for low energy and libido while still planning children. That combination is exactly where testosterone therapy in NYC needs the most careful planning.

Sperm banks and male fertility specialists are widely available in Manhattan, which makes banking before TRT a realistic step. We coordinate with these specialists when a patient's plan calls for it.

At Liondale Medical, the fertility conversation happens before any prescription. Dr. Bissoon starts with the full hormone picture: confirmed morning testosterone, LH and FSH, estradiol, prolactin, and a review of the habits and medications that can lower testosterone on their own. Then the question becomes practical: what are you hoping to feel, and what is your family timeline?

For a man with no plans for biological children, standard testosterone therapy with careful monitoring may be the right path. For a man who wants children, or simply wants to keep that option open, the plan may lean toward approaches that support the body's own production, with baseline semen analysis and sperm banking discussed up front. For men already on testosterone who have changed their plans, the focus is a structured transition and coordination with fertility specialists when needed.

Frequently Asked Questions

Does TRT make you infertile?

TRT often reduces sperm production and can cause azoospermia, meaning no sperm in the semen. This happens because injected testosterone suppresses LH and FSH, the pituitary hormones that drive sperm production and testosterone inside the testicles. For most men the effect is reversible after stopping, typically over six to twenty-four months, but recovery is not guaranteed for everyone. That is why men who want children now or later are generally advised not to use testosterone alone and to consider a baseline semen analysis and sperm banking first.

What do testosterone shots do for men?

Testosterone shots raise blood testosterone levels in men who are deficient. In men with confirmed low testosterone and symptoms, restoring normal levels can improve libido, energy, mood, muscle mass, and bone density, though results vary. The shots replace rather than stimulate your own production, so your brain reduces the signals to your testicles. That is why testosterone shots can shrink the testicles and lower sperm counts, an important consideration for any man who may want biological children.

What is a TRT injection?

A TRT injection is a dose of testosterone, usually testosterone cypionate or enanthate, given into a muscle or under the skin on a set schedule, often weekly or every one to two weeks. It is a form of testosterone replacement therapy used to treat confirmed testosterone deficiency. Dosing is adjusted based on symptoms and blood tests, including testosterone, hematocrit, estradiol, and PSA where appropriate. Fertility should be discussed before the first injection.

What are the side effects of testosterone shots?

Common side effects of testosterone shots include reduced sperm production, testicular shrinkage, increased hematocrit (thicker blood), acne, oily skin, breast tenderness, fluid retention, and mood changes around dose peaks. Testosterone can worsen untreated sleep apnea and can change PSA levels. Most are manageable with monitoring and dose adjustments, and several overlap with the warning signs of a testosterone imbalance. Fertility suppression deserves special attention because recovery after stopping can take months and is not certain for every man.

How long does it take for sperm to come back after stopping TRT?

Sperm take about two and a half months to develop, so recovery usually is not visible on a semen analysis until at least three months after stopping. Many men recover meaningful counts within six to twelve months, and most recover within two years. Longer use, higher doses, older age, and pre-existing testicular problems can slow recovery. Medications such as hCG or clomiphene are sometimes used to help restart natural production under medical supervision.

Can hCG protect fertility while on testosterone?

hCG mimics LH and stimulates the testicles to produce testosterone internally, which can help maintain testicular size and sperm production in many men taking low dose testosterone. It is not a guarantee, because it does not replace FSH and responses vary. Men who want to conceive in the near term are often better served by avoiding testosterone and using hCG or clomiphene on their own. Regular semen analyses are the only way to confirm that a combined plan is working.

Is clomiphene a good alternative to TRT for men who want children?

For many men with secondary hypogonadism, meaning low testosterone with low or normal LH and FSH, clomiphene can raise both testosterone and sperm production by blocking estrogen feedback at the brain. It is taken by mouth and is used off-label in men. It works less well when the testicles themselves are the problem. Side effects can include mood changes, headaches, and rare visual symptoms, so it requires physician supervision and follow up labs.

Should I bank sperm before starting testosterone?

If biological children matter to you at any point, sperm banking before starting testosterone is the most reliable insurance available. Most men recover sperm production after stopping TRT, but not all, and there is no reliable way to predict who will not. Banking usually involves a few collections that are frozen and stored for future use with insemination or IVF. Pair it with a baseline semen analysis so you know your starting point.

What labs should I ask for before starting TRT?

Ask for two early morning total testosterone tests on separate days, free testosterone and SHBG, LH and FSH, estradiol, prolactin, a complete blood count, and PSA when age-appropriate. If fertility matters, add a semen analysis, ideally two samples. Metabolic tests and thyroid tests can identify other causes of fatigue. Dr. Lionel Bissoon reviews these results together, because a single number rarely tells the full story about symptoms or fertility.

This page was written and medically reviewed by Lionel Bissoon, D.O., founder of Liondale Medical. Dr. Bissoon is a board-certified osteopathic physician specializing in anti-aging and concierge medicine on the Upper West Side of Manhattan.

This content is for educational purposes only and does not constitute medical advice. Individual results may vary. Consult a qualified physician before beginning any new treatment.

Published October 6th, 2026