What Is the Connection and What Should You Do Next?

Low testosterone is one of the most frequently discussed hormonal concerns in men, particularly among those experiencing infertility, reduced sexual desire, erectile difficulties, fatigue, loss of muscle strength, or abnormal semen analysis.

However, the relationship between testosterone and male fertility is often misunderstood.

Many men assume that if their testosterone level is low, taking testosterone injections, gels, capsules, or other testosterone products will automatically improve sperm production and fertility. In reality, the situation can be very different. External testosterone can suppress the hormonal signals required for sperm production and may substantially reduce sperm count or even cause azoospermia in some men. Current AUA/ASRM male-infertility guidance therefore states that testosterone monotherapy should not be prescribed to men interested in current or future fertility. ASRM

For this reason, low testosterone in a man trying to father a child requires a fertility-focused hormonal evaluation, rather than simply attempting to increase the testosterone number.

Saira Health Care's latest educational video discusses this important issue:

Low Testosterone & Infertility

Watch the full video on YouTube

What Is Testosterone?

Testosterone is the principal androgen hormone in men.

Most testosterone is produced by the Leydig cells inside the testes under stimulation from another hormone called luteinizing hormone (LH), which is released by the pituitary gland.

Testosterone contributes to several important functions, including:

• Development and maintenance of male sexual characteristics
• Sexual desire
• Muscle mass and strength
• Bone health
• Red blood-cell production
• General sense of wellbeing
• Reproductive and testicular function

Testosterone also plays an important role in creating the hormonal environment required for normal sperm production.

However, blood testosterone and fertility are not the same thing. A man cannot determine whether he is fertile simply by checking his testosterone level.

How Is Testosterone Connected With Sperm Production?

Normal sperm production depends on an interconnected hormonal system commonly called the hypothalamic-pituitary-gonadal axis.

The brain releases hormonal signals that stimulate the pituitary gland.

The pituitary then releases:

LH — Luteinizing Hormone

and

FSH — Follicle-Stimulating Hormone

LH stimulates Leydig cells within the testes to produce testosterone.

FSH acts primarily on Sertoli cells and supports spermatogenesis—the process through which sperm cells develop and mature.

Therefore, male fertility depends on the coordinated activity of:

Brain → Pituitary → LH & FSH → Testes → Testosterone & Sperm Production

Problems at any point in this system may contribute to hormonal abnormalities or infertility.

Does Low Testosterone Cause Infertility?

Low testosterone can be associated with male infertility, but a low testosterone result does not automatically mean that a man is infertile.

Some men with low circulating testosterone may continue to produce sperm.

Other men may have low testosterone together with:

• Low sperm concentration
• Poor sperm motility
• Abnormal sperm production
• Azoospermia
• Reduced libido
• Erectile problems
• Other hormonal abnormalities

For this reason, fertility cannot be assessed from testosterone alone.

A man who is concerned about fertility generally needs a semen analysis, because this directly evaluates important sperm parameters.

The AUA/ASRM male-infertility guideline emphasizes semen analysis as a central component of male fertility evaluation and recommends hormonal assessment in selected men, particularly those with oligozoospermia or other findings suggesting an endocrine abnormality. ASRM

What Are the Symptoms of Low Testosterone?

Symptoms vary considerably from one man to another.

Possible symptoms may include:

• Reduced sexual desire
• Decreased spontaneous erections
• Erectile difficulties
• Reduced energy
• Fatigue
• Loss of muscle mass
• Reduced physical strength
• Changes in mood
• Reduced body or facial hair
• Reduced testicular volume in some conditions
• Reduced fertility
• Low bone density in longstanding cases
• Anemia in certain men

However, these symptoms are not specific to testosterone deficiency.

Fatigue, reduced libido, poor sleep, stress, obesity, depression, medications, chronic disease and several other conditions can produce similar complaints.

The Endocrine Society's 2026 statement emphasizes that symptoms alone cannot diagnose testosterone deficiency; diagnosis requires appropriate symptoms together with consistently low testosterone measured accurately. Endocrine

One Low Testosterone Test Is Usually Not Enough

This is particularly important.

Testosterone levels naturally fluctuate.

They can be influenced by:

• Time of day
• Sleep
• Acute illness
• Nutrition
• Obesity
• Medications
• Laboratory method
• Stress and general health

Because of this variation, a single low result should not automatically lead to a diagnosis of hypogonadism or immediate testosterone treatment.

The Endocrine Society recommends diagnosing hypogonadism only when a man has relevant symptoms or signs together with unequivocally and consistently low testosterone, and recommends confirming the finding with a repeat morning fasting total testosterone measurement. Endocrine

Its July 2026 statement further emphasizes diagnosis based on at least two early-morning testosterone tests performed with appropriate assays. Endocrine

Therefore:

One abnormal laboratory number ≠ automatic diagnosis.

What Can Cause Low Testosterone?

There are many possible causes.

Understanding the cause is essential because treatment differs significantly depending on whether the problem arises in the testes or in the brain/pituitary hormonal system.

Primary Testicular Causes

In primary hypogonadism, the testes themselves may not produce testosterone normally.

Possible causes can include:

• Significant testicular injury
• Previous testicular infection
• Certain genetic conditions
• Previous chemotherapy
• Previous radiation treatment
• Testicular disorders
• Some congenital abnormalities

In these situations, LH and FSH may often be elevated because the pituitary is attempting to stimulate under-functioning testes.

Secondary Hormonal Causes

Sometimes the testes may be capable of functioning, but the brain or pituitary gland does not provide adequate stimulation.

Possible causes include:

• Pituitary disorders
• Hypothalamic disorders
• Elevated prolactin
• Certain medications
• Severe obesity
• Chronic illness
• Some genetic disorders
• Previous pituitary surgery or treatment

The Endocrine Society recommends measuring LH and FSH in men with confirmed hypogonadism to help distinguish primary testicular disease from secondary hypothalamic or pituitary causes. Endocrine

Obesity and Low Testosterone

Obesity deserves special attention because it is common and potentially modifiable.

Men who are overweight or obese may have lower total testosterone concentrations, and several metabolic and hormonal mechanisms may contribute.

The Endocrine Society's 2026 statement emphasizes that reversible contributors—particularly obesity and certain medications—should be considered before automatically prescribing testosterone. For appropriately diagnosed low testosterone associated with excess weight and no other identified pathological cause, weight reduction is generally an important first-line consideration. Endocrine

This does not mean that every overweight man with low testosterone can correct the problem through weight loss alone.

It means that the underlying cause should be addressed rather than merely treating a laboratory value.

Medicines Can Affect Testosterone

Certain medications may contribute to low testosterone or interfere with reproductive hormonal function.

Examples can include some opioid pain medicines and corticosteroids, among others.

The Endocrine Society also lists chronic kidney or liver disease, sleep disorders, type 2 diabetes, HIV, obesity, pituitary disorders and certain genetic conditions among recognized contributors to male hypogonadism. Endocrine

Patients should never stop a prescribed medicine without discussing it with the prescribing healthcare professional.

Anabolic Steroids and Male Fertility

Men who use anabolic steroids for bodybuilding may experience serious disruption of normal reproductive hormone production.

When the body receives external androgens, the brain may reduce its production of signals to the pituitary gland.

LH and FSH can fall.

As a result:

Testicular testosterone production may fall → sperm production may decline → testicular size may decrease → fertility may become impaired.

This is why a muscular appearance or high blood testosterone after steroid use does not necessarily mean reproductive function is healthy.

Anabolic steroid use is a recognized potential contributor to hypogonadism. Endocrine

Testosterone Replacement Therapy and Infertility: A Critical Point

This is perhaps the most important part of this discussion.

A man with low testosterone may naturally think:

“If testosterone is low, I should take testosterone.”

For a man who is not concerned about fertility and has properly diagnosed hypogonadism, testosterone replacement therapy can sometimes be appropriate under medical supervision.

But for a man who wants children, the situation is different.

External testosterone can suppress sperm production.

Testosterone injections, gels, patches, pellets and other systemic testosterone therapies provide testosterone from outside the body.

The brain senses this testosterone and reduces stimulation of the pituitary gland.

As LH and FSH fall, the testes receive less stimulation.

The concentration of testosterone inside the testes, which is important for spermatogenesis, may decrease significantly.

Consequently:

External testosterone → LH/FSH suppression → reduced testicular stimulation → reduced sperm production

In some men, sperm production can become severely reduced or stop altogether.

The AUA/ASRM guideline explains that exogenous testosterone may inhibit gonadotropin secretion and can reduce spermatogenesis or produce azoospermia. Accordingly, it states that testosterone monotherapy should not be prescribed to a man interested in current or future fertility. ASRM

The Endocrine Society likewise recommends against starting testosterone therapy in men planning fertility in the near term. Endocrine

Can Testosterone Treatment Cause Zero Sperm?

Yes, in some men.

Suppression of LH and FSH caused by external testosterone can become strong enough that sperm production falls dramatically.

This may produce:

• Severe oligozoospermia
• Cryptozoospermia
• Azoospermia

The degree of suppression varies from person to person.

Importantly, recovery after testosterone discontinuation is not necessarily immediate.

Men who have used testosterone for an extended period should therefore be assessed by a clinician experienced in male reproductive endocrinology or infertility rather than trying to correct the situation independently.

Never Stop Prescribed Testosterone Suddenly Without Medical Advice

Although testosterone may interfere with fertility, a patient already receiving medically prescribed testosterone should not simply stop treatment based on an online article.

The patient's original diagnosis, dose, duration, underlying endocrine condition and fertility goals should be reviewed.

A specialist can decide how treatment should be modified and what investigations or fertility-preserving strategies may be appropriate.

What Tests Are Useful in a Man With Low Testosterone and Infertility?

Evaluation should be individualized, but may include the following.

1. Repeat Morning Testosterone

Low testosterone should generally be confirmed appropriately rather than diagnosed from one random test.

The Endocrine Society recommends repeat morning fasting measurement when confirming testosterone deficiency. Endocrine

2. Semen Analysis

For a man concerned about fertility, semen analysis is extremely important.

It may provide information about:

• Sperm concentration
• Total sperm number
• Sperm motility
• Sperm morphology
• Semen volume
• Presence or absence of sperm

The hormonal report cannot replace the semen report.

3. FSH

FSH provides important information regarding stimulation of sperm-producing cells.

High FSH together with severely abnormal sperm production may suggest primary testicular dysfunction.

Low or inappropriately normal FSH in a man with low testosterone may suggest a central hormonal problem.

4. LH

LH helps determine whether low testosterone is more likely to originate from the testes or the hypothalamic-pituitary system.

For example:

Low testosterone + high LH may suggest primary testicular dysfunction.

Low testosterone + low/inappropriately normal LH may suggest secondary hypogonadism.

This distinction can substantially change the treatment approach.

5. Prolactin

In selected men with low testosterone together with low or low-normal LH, particularly when decreased libido or other appropriate clinical findings are present, prolactin may be measured.

The AUA/ASRM guideline recommends investigation for hyperprolactinemia in appropriate infertile men and further evaluation of persistently elevated prolactin when necessary. ASRM

6. Other Investigations

Depending on the individual patient, clinicians may also consider:

• Thyroid testing
• Iron-related investigations
• Metabolic testing
• Pituitary evaluation
• Scrotal examination
• Ultrasound when indicated
• Genetic evaluation in selected severe infertility cases
• Additional endocrine testing

Not every patient requires every test.

Low Testosterone With Low Sperm Count

When both testosterone and sperm concentration are low, the clinician needs to identify whether these abnormalities share the same underlying cause.

Possible explanations include:

• Hypothalamic or pituitary hormonal dysfunction
• Testicular disease
• Medication effects
• Anabolic steroid use
• Significant obesity or metabolic disease
• Genetic or congenital conditions
• Previous testicular damage
• Other reproductive disorders

It is therefore inappropriate to conclude:

“The sperm count is low only because testosterone is low.”

Both findings require interpretation in context.

Low Testosterone With Azoospermia

A man who has both low testosterone and azoospermia requires careful evaluation.

Azoospermia means no sperm are identified in the ejaculate after appropriate laboratory assessment.

The AUA/ASRM guideline states that history, examination and hormonal findings can help distinguish obstructive azoospermia from non-obstructive azoospermia caused by impaired sperm production. ASRM

Hormone results—including FSH, LH and testosterone—can therefore provide valuable diagnostic information.

But they should never be used alone to determine prognosis.

Can Low Testosterone Be Treated Without Damaging Fertility?

Sometimes, depending on the cause.

This is where distinguishing between ordinary testosterone replacement and fertility-preserving endocrine treatment becomes important.

For infertile men with low testosterone, AUA/ASRM guidance states that clinicians may consider selected therapies such as:

• Human chorionic gonadotropin (hCG)
• Selective estrogen receptor modulators (SERMs)
• Aromatase inhibitors
• Certain combinations

depending on the patient's hormonal pattern and underlying condition. The evidence and appropriateness differ by patient, so these are specialist treatments rather than medicines for self-use. ASRM

Not every man with low testosterone needs these medicines.

Not every man responds similarly.

Diagnosis comes first.

Fertility Treatment Should Focus on the Cause

Suppose three men all have low testosterone.

Patient A

He has low testosterone, low LH and low FSH due to a pituitary or hypothalamic disorder.

Patient B

He has low testosterone with markedly elevated LH and FSH because of primary testicular dysfunction.

Patient C

He has low testosterone associated with obesity and another reversible metabolic factor.

Although all three reports say “low testosterone,” the underlying biology and treatment strategies may be completely different.

This is why prescribing identical treatment to every man with a low testosterone result is inappropriate.

What About Sexual Desire and Erectile Function?

Low testosterone may contribute to reduced libido in some men.

It may also contribute to sexual symptoms in appropriately diagnosed hypogonadism.

However, erectile dysfunction is multifactorial.

Erection problems can be associated with:

• Diabetes
• Cardiovascular disease
• High blood pressure
• Anxiety
• Performance anxiety
• Medications
• Relationship factors
• Neurological conditions
• Smoking
• Obesity
• Sleep problems
• Hormonal disorders

Therefore, a man experiencing erectile difficulty should not automatically assume that low testosterone is the sole cause.

Low Testosterone Does Not Always Mean Low Masculinity

Another important issue is the emotional impact of receiving a low testosterone report.

Patients sometimes associate testosterone levels with masculinity, sexual worth or fertility.

This can create unnecessary anxiety.

A laboratory result is a medical measurement, not a judgment of masculinity.

Low testosterone can occur because of several biological, metabolic, endocrine, medication-related or testicular conditions.

The correct response is evaluation—not embarrassment.

Does Age Cause Low Testosterone?

Testosterone concentrations may change with aging, but a lower number in an older man should not automatically be labelled a disease requiring testosterone treatment.

The Endocrine Society stresses that diagnosis requires symptoms plus consistently low testosterone, regardless of age, and that terms such as “age-related” hypogonadism can blur the distinction between disease and normal aging. Endocrine

Therefore, testosterone should not be prescribed merely because a man wants to “feel younger” or because of one borderline laboratory value.

Lifestyle and Testosterone

Healthy lifestyle measures can support general hormonal and reproductive health.

These may include:

• Maintaining an appropriate body weight
• Regular physical activity
• Adequate sleep
• Avoiding anabolic steroids
• Avoiding recreational drugs
• Stopping smoking
• Limiting excessive alcohol
• Managing diabetes and metabolic conditions
• Reviewing medications with a healthcare professional

Lifestyle improvement cannot correct every cause of hypogonadism, but it may be particularly relevant when obesity, sleep disorders or metabolic health are contributing factors.

Can Supplements Increase Testosterone and Cure Infertility?

Patients should be cautious.

The market contains numerous products claiming to:

“Boost testosterone.”

“Increase sperm immediately.”

“Restore male power.”

“Reverse infertility.”

These claims may not be supported by strong clinical evidence.

AUA/ASRM guidance states that the clinical usefulness of antioxidant and vitamin supplementation for male infertility is questionable and that available data are inadequate to recommend specific agents as a general fertility treatment. ASRM

Supplements should not replace diagnosis of an underlying hormonal, genetic, testicular or reproductive condition.

When Should a Man Seek Medical Evaluation?

Professional assessment should be considered if a man has:

• Persistent symptoms suggestive of testosterone deficiency
• Repeatedly low testosterone results
• Difficulty conceiving
• Low sperm count
• Azoospermia
• Reduced sexual desire
• Erectile difficulties
• Changes in testicular size
• Previous testicular injury
• Previous chemotherapy or radiation
• History of anabolic steroid use
• Pituitary disease
• Abnormal FSH or LH
• Other significant endocrine symptoms

Men trying to conceive should mention their fertility goals before receiving hormonal treatment.

That single discussion may significantly influence the safest treatment strategy.

A Better Approach to Low Testosterone and Infertility

Instead of asking only:

“How can I increase my testosterone?”

a man experiencing infertility should ask:

“Why is my testosterone low?”

The appropriate clinical pathway may look like this:

Symptoms or Fertility Concern
↓
Morning Testosterone Test
↓
Confirm Low Testosterone When Appropriate
↓
Check LH / FSH and Other Relevant Hormones
↓
Semen Analysis
↓
Identify Testicular vs. Pituitary/Hypothalamic Cause
↓
Assess Medicines, Lifestyle and Medical Conditions
↓
Choose Fertility-Preserving Treatment When Needed

This approach addresses the actual condition rather than simply chasing a laboratory number.

Low Testosterone and Infertility: The Most Important Message

Men planning fatherhood should remember three important points.

First: Low testosterone may occur together with male infertility, but a low testosterone report alone does not tell us whether a man is fertile.

Second: Fertility assessment usually requires semen analysis and, when indicated, additional hormonal and clinical evaluation.

Third: Standard testosterone replacement can suppress sperm production, which is why testosterone monotherapy is generally inappropriate for men actively trying to conceive or wishing to preserve near-term fertility. Endocrine

The treatment goal should therefore not simply be:

“Make testosterone higher.”

It should be:

“Identify the underlying problem while protecting reproductive function.”

Watch Our Video: Low Testosterone & Infertility

In this Saira Health Care educational video, we explain:

✅ What low testosterone means
✅ How testosterone affects male reproductive health
✅ Testosterone and sperm production
✅ Low testosterone and low sperm count
✅ Low testosterone and azoospermia
✅ FSH and LH testing
✅ Why semen analysis matters
✅ Testosterone therapy and fertility
✅ Why external testosterone can reduce sperm production
✅ What investigations may be needed
✅ Why treatment should be individualized

Watch “Low Testosterone & Infertility” on YouTube

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Medical Disclaimer

This article is intended for general education and health awareness only. It should not be used for self-diagnosis or as a substitute for individual consultation, physical examination, semen analysis, hormonal investigations or professional medical treatment.

Low testosterone should generally be diagnosed on the basis of compatible symptoms or signs together with appropriately confirmed low testosterone concentrations. Treatment depends on the underlying cause, symptoms, reproductive goals and other medical considerations. Endocrine

Men who are trying to conceive should not start testosterone injections, gels or other testosterone therapies without discussing fertility with an appropriately qualified healthcare professional, because external testosterone can suppress sperm production.