Can Testosterone Replacement Therapy Affect Fertility?

Yes. Testosterone replacement therapy (TRT) can significantly reduce male fertility because external testosterone can suppress the hormonal signals the testicles need to produce sperm. In some men, sperm counts fall substantially; in others, sperm production may temporarily stop altogether.

This is one of the most important considerations for younger men or anyone who may want biological children in the future.

The Endocrine Society recommends against starting testosterone therapy in men who are planning fertility in the near term, while American Urological Association guidance recommends discussing the potential long-term effect of external testosterone on sperm production with men interested in future fertility.

If having children now or in the future is important to you, discuss your reproductive plans before starting TRT. Depending on the reason your testosterone is low, alternatives that better preserve sperm production may sometimes be available.

For a broader overview of testosterone treatment, read Testosterone Replacement Therapy (TRT): What Every Man Should Know.

Why Can Testosterone Lower Sperm Production?

It may seem contradictory that testosterone—a hormone necessary for normal male reproductive function—can reduce fertility when it is given as a medication.

The explanation involves how the brain and testicles communicate.

Normally, the hypothalamus and pituitary gland release signals that stimulate the testicles. Two particularly important hormones are:

• Luteinizing hormone (LH), which stimulates testosterone production inside the testicles.

• Follicle-stimulating hormone (FSH), which helps support sperm production.

When testosterone is supplied from outside the body through injections, gels, pellets, oral medications, or other testosterone products, the brain senses the increased circulating testosterone. Through a negative-feedback mechanism, the hypothalamus and pituitary gland may reduce their production of the signals that normally stimulate the testicles.

LH and FSH can therefore decrease.

As a result, testosterone production inside the testicles can fall substantially, even though the testosterone level measured in the bloodstream may look normal or elevated. Because adequate intratesticular testosterone and gonadotropin signaling are important for sperm production, spermatogenesis can decline.

This is why someone can have an excellent blood testosterone level while simultaneously having a very low sperm count.

How Much Can TRT Lower Sperm Count?

The effect varies considerably from person to person.

Some men continue producing sperm while taking testosterone, but their sperm concentration may fall. Other men may develop oligospermia, meaning a very low sperm count.

Some may develop azoospermia, meaning no sperm are detected in the ejaculate.

Because individual responses vary, you should not assume that normal sexual function, normal ejaculation, or a normal testosterone level means sperm production is normal.

TRT can improve libido, erections, energy, or other symptoms in appropriately selected men while fertility is declining at the same time. Sexual function and sperm production are related to reproductive health, but they are not the same thing.

Does Every Type of TRT Affect Fertility?

Potentially, yes.

The fertility issue is not limited to testosterone injections.

Exogenous testosterone can suppress the hypothalamic-pituitary-gonadal axis whether testosterone is administered as:

• Injections

• Topical gels or creams

• Testosterone patches

• Implantable pellets

• Oral testosterone preparations

• Other systemic testosterone formulations

Different formulations have different pharmacologic characteristics, but switching from an injection to another form of testosterone should not automatically be considered a fertility-preserving strategy.

You can learn more about the different forms of hormone treatment in Types of HRT: Pills, Patches, Gels, Injections, and Pellets.

Is Infertility From TRT Permanent?

Not necessarily. Sperm production often improves after testosterone is discontinued, but recovery can take time and cannot be guaranteed for every man.

The AUA notes that recovery after stopping external testosterone is highly variable. Data from hormonal male-contraception studies found that approximately two-thirds of men had sperm return to the ejaculate within six months after testosterone was stopped, while approximately 10% did not recover sperm until the second year. Those numbers cannot necessarily be applied directly to every man receiving TRT because baseline fertility, age, duration of therapy, underlying health conditions, and the original cause of low testosterone may differ.

Recovery may therefore occur over several months and, in some cases, considerably longer.

Some men may also have had impaired fertility before starting testosterone. Stopping TRT cannot necessarily reverse infertility that existed for another reason.

This is why evaluating reproductive goals before treatment is preferable to discovering a fertility problem after years of testosterone use.

What Affects Fertility Recovery After Stopping TRT?

Several factors may influence how quickly sperm production returns, including:

• Age

• How long testosterone has been used

• Testosterone dose and exposure

• Baseline sperm production

• Baseline testicular function

• Whether the underlying testosterone deficiency is primary or secondary

• Previous anabolic steroid use

• Other medications

• Testicular disorders

• Pituitary or hypothalamic disorders

• Genetic conditions

• Previous chemotherapy or radiation

• Other causes of male infertility

Research has found that increasing age and longer durations of testosterone use can be associated with slower sperm recovery following treatment for testosterone-associated infertility.

Because these situations can be complicated, men experiencing infertility after TRT may benefit from evaluation by a urologist specializing in male reproductive medicine or another fertility specialist.

What If I Want Children in the Near Future?

Tell your physician before starting testosterone.

This conversation should ideally occur even if you are not trying to conceive immediately.

For example, you may not want children this year but may want them several years from now. That information can still influence treatment decisions.

The American Urological Association recommends a reproductive health evaluation before treatment in men with testosterone deficiency who are interested in fertility. The Endocrine Society similarly recommends against starting conventional testosterone therapy when fertility is planned in the near term.

Before treatment, your evaluation may include discussion of:

• Whether you currently have children

• Whether you want biological children in the future

• Your expected timeline for trying to conceive

• Previous fertility problems

• Testicular or reproductive conditions

• Prior testosterone or anabolic steroid use

• Medications that could affect fertility

• Whether semen analysis is appropriate

• Whether fertility preservation should be considered

Fertility goals are therefore part of the medical history—not an afterthought once treatment has already begun.

Should I Have a Semen Analysis Before Starting TRT?

Not every man considering TRT needs a semen analysis.

However, it may be reasonable to consider one when fertility is an important treatment consideration, particularly if you are planning pregnancy, have a history suggesting possible infertility, or want information about your baseline sperm production before beginning a therapy that may suppress it.

A semen analysis can evaluate characteristics such as:

• Sperm concentration

• Total sperm count

• Motility

• Semen volume

• Morphology and other parameters when appropriate

If future fertility is especially important, your physician may recommend consultation with a reproductive urologist or fertility specialist before treatment.

Can Low Testosterone Be Treated Without Standard TRT When Fertility Matters?

Sometimes.

The appropriate strategy depends heavily on why testosterone is low.

Standard TRT supplies testosterone from outside the body. In certain men, another approach may instead attempt to stimulate or preserve the body's own testosterone production and reproductive signaling.

Depending on the clinical situation, specialists may consider treatments such as:

• Human chorionic gonadotropin (hCG)

• Selective estrogen receptor modulators (SERMs)

• Aromatase inhibitors

• Combinations of these therapies in selected circumstances

AUA guidance allows clinicians to consider these approaches in men with testosterone deficiency who want to maintain fertility, although the evidence, indications, regulatory status, risks, and monitoring requirements differ among the medications. They should not be viewed as interchangeable replacements for TRT or used without medical supervision.

The underlying cause matters considerably.

For example, a man whose testes cannot adequately produce testosterone may have a different situation from someone whose pituitary-hypothalamic signaling is impaired.

That is one reason low testosterone should be properly diagnosed before treatment begins. Read How Is Low Testosterone Diagnosed? for a more detailed explanation.

What If I Am Already Taking TRT and Now Want to Have a Child?

Do not panic, and do not make major medication changes without discussing them with the physician managing your care.

A medical evaluation can help determine:

1. What testosterone treatment you are currently using.

2. How long you have been using it.

3. Whether there were fertility concerns before treatment.

4. Whether semen analysis is appropriate.

5. Whether TRT should be discontinued or modified.

6. Whether fertility-directed medication may be appropriate.

7. Whether evaluation by a reproductive urologist is warranted.

In many men, sperm production can return after testosterone is stopped, but recovery may take months or longer. AUA guidance also recognizes that some men may not completely recover their previous sperm production after discontinuing testosterone.

If pregnancy is desired soon, involving a male-fertility specialist early can be helpful rather than simply stopping testosterone and waiting indefinitely.

Can I Bank Sperm Before Starting Testosterone?

Sperm cryopreservation may be worth discussing if preserving future biological fertility is particularly important.

This does not mean every young man considering TRT needs to freeze sperm.

It may be more relevant when:

• Fertility is a major priority.

• Baseline sperm production is already reduced.

• Long-term testosterone treatment is anticipated.

• There are additional reproductive risk factors.

• Future fertility timing is uncertain.

• A reproductive specialist believes fertility preservation would be prudent.

A semen analysis can also provide useful baseline information before making this decision.

Does Having Low Testosterone Already Mean I Am Infertile?

No.

Low testosterone and male infertility can occur together, but they are not synonymous.

Some men with low testosterone maintain adequate sperm production, while others have impaired fertility.

Likewise, men can have normal blood testosterone levels and still have infertility due to sperm abnormalities, obstruction, varicocele, genetic conditions, testicular disorders, medication effects, or many other causes.

Testosterone deficiency itself should be diagnosed using compatible symptoms or clinical findings together with appropriately confirmed low testosterone levels. Additional testing such as LH and FSH can help determine whether the problem appears to originate primarily from the testes or from pituitary-hypothalamic signaling.

For more information, see Low Testosterone in Men: Symptoms, Diagnosis, and Treatment Options.

Why Fertility Goals Should Be Discussed Before Starting TRT

TRT can be an appropriate treatment for selected men with confirmed testosterone deficiency, but treatment decisions should consider more than the testosterone number.

Important factors include:

• Symptoms

• Repeated testosterone measurements

• Cause of the testosterone deficiency

• Age

• Medical history

• Current medications

• Cardiovascular and metabolic health

• Hematocrit

• Prostate considerations when appropriate

• Treatment preferences

• Current and future fertility goals

If you are considering testosterone treatment, our guide to laboratory testing before hormone replacement therapy explains some of the evaluation that may be considered before therapy begins.

Frequently Asked Questions

Can TRT make a man infertile?

Yes. External testosterone can substantially suppress sperm production and may lead to very low sperm counts or azoospermia in some men. This is why fertility plans should be discussed before starting testosterone therapy.

Can fertility return after stopping TRT?

Often, but recovery is variable. Sperm production may return within several months for some men, while others may require a year or longer. Complete recovery to a man's previous fertility level cannot be guaranteed.

Can I take testosterone while trying to have a baby?

Standard exogenous testosterone therapy is generally not recommended for men actively attempting conception. The Endocrine Society recommends against testosterone therapy in men planning fertility in the near term, and AUA guidance similarly advises against exogenous testosterone in men currently trying to conceive.

Are there alternatives to TRT if I want to preserve fertility?

Potentially. Depending on the cause of testosterone deficiency, clinicians may consider treatments that stimulate endogenous hormone production, including hCG, SERMs, aromatase inhibitors, or selected combinations. These treatments require individualized medical evaluation and monitoring.

Should I tell my doctor that I may want children even if that is years away?

Yes. Future fertility can influence how testosterone deficiency is evaluated and treated, so reproductive goals should be discussed before therapy whenever possible.

The Bottom Line

Testosterone replacement therapy can affect fertility because external testosterone may suppress LH and FSH signaling, decrease testosterone production inside the testicles, and reduce or temporarily stop sperm production.

For many men, sperm production improves after TRT is discontinued, but recovery can take months or longer and may not be complete in every patient.

If having biological children now or in the future matters to you, discuss fertility before starting testosterone. Depending on your diagnosis and reproductive goals, your physician may recommend additional evaluation, semen testing, fertility preservation, alternative treatment strategies, or referral to a male reproductive specialist.

TRT is therefore not simply a decision about improving a testosterone laboratory value. It should be part of an individualized discussion that considers your symptoms, medical history, laboratory findings, treatment goals, risks, and reproductive plans.

You can explore additional physician-written information in the Hormone Replacement Therapy Resource Center.

If you are considering treatment in Arizona, learn more about personalized hormone replacement therapy at Ask Dr. Hu.

Medical Review & Evidence Standards

This article was developed using established clinical guidance regarding testosterone deficiency and male reproductive health.

Authoritative references include:

• American Urological Association — Testosterone Deficiency Guideline, which addresses testosterone treatment, reproductive considerations, and fertility-preserving treatment strategies.

• American Urological Association / American Society for Reproductive Medicine — Male Infertility Guideline, which addresses evaluation and management of male infertility and the effects of external testosterone on spermatogenesis.

• Endocrine Society — Testosterone Therapy for Hypogonadism Clinical Practice Guideline, which recommends appropriate diagnostic evaluation and advises against testosterone therapy when fertility is planned in the near term.

Clinical recommendations and treatment options may change as additional evidence becomes available. Testosterone treatment and fertility management should be individualized according to the patient's diagnosis, reproductive goals, health history, laboratory findings, and response to treatment.

Published August 2026 | Medically reviewed August 2026

This information is intended for general educational purposes and does not replace individualized medical advice, diagnosis, or treatment and does not establish a physician-patient relationship.

About the Author

YiQiu Hu, NMD, is an Arizona-licensed naturopathic physician and founder of Ask Dr. Hu. He provides concierge medicine, preventive healthcare, health optimization, laboratory evaluation, hormone care, and individualized medical treatment for adults throughout Arizona.

Dr. Hu earned his Doctor of Naturopathic Medicine degree from Sonoran University of Health Sciences and a Bachelor of Science in Biomedical Sciences from Northern Arizona University. His clinical approach emphasizes comprehensive medical evaluation, thoughtful laboratory interpretation, evidence-informed decision-making, clear patient education, and individualized treatment planning.

Learn more about Dr. YiQiu Hu and the physicians at Ask Dr. Hu.