Testosterone Deficiency in Men: Symptoms, Causes, and When to Get Tested

Testosterone deficiency in men, also called male hypogonadism, most often shows up as low sex drive, fewer erections, fatigue, loss of muscle or strength, more body fat, low mood, and trouble focusing. Sexual symptoms are the most specific. Diagnosis requires symptoms plus low morning testosterone, usually confirmed on a repeat test 1.

What is testosterone deficiency in men?

Testosterone deficiency means the testes do not make enough testosterone for a man’s body, or the brain signals that control testosterone are not working normally. Clinicians also call this male hypogonadism. The diagnosis is not based on symptoms alone; the Endocrine Society guideline says men should have both compatible symptoms and “unequivocally and consistently” low testosterone levels 1.

Testosterone helps regulate sexual desire, erections, sperm production, red blood cell production, bone density, muscle mass, and fat distribution. Levels also change across the day, with higher levels earlier in the morning in many men, which is why timing matters for testing 1.

There are two broad types. Primary hypogonadism starts in the testes. Secondary hypogonadism starts in the hypothalamus or pituitary, the brain centers that send hormonal signals to the testes. Late-onset hypogonadism, or LOH, refers to low testosterone symptoms and levels that develop with aging, often alongside obesity, chronic disease, or medications 3.

What are the symptoms of low testosterone in men?

Low testosterone symptoms fall into sexual, physical, and mood-energy groups. Sexual symptoms are the most specific, while fatigue, low mood, and weight gain can come from many other causes. In the European Male Ageing Study, the combination of low sexual thoughts, fewer morning erections, and erectile dysfunction had the clearest link with low testosterone 3.

Sexual symptoms that are most specific

• Lower sex drive or fewer sexual thoughts
• Fewer morning erections
• New or worsening erectile dysfunction
• Lower semen volume or fertility concerns
• Reduced testicular size in some men

Erectile dysfunction can happen even when testosterone is normal because erections also depend on blood flow, nerves, mood, sleep, and medication effects. That is why a clinician will usually ask about heart risk factors, diabetes, blood pressure, smoking, alcohol, and mental health before assuming testosterone is the only cause 2.

Physical symptoms

• Loss of muscle mass or strength
• More body fat, especially around the waist
• Lower bone density or fractures with minor trauma
• Hot flashes or sweats in more severe cases
• Breast tenderness or breast tissue growth
• Anemia, which can feel like weakness or shortness of breath

Low testosterone can contribute to lower bone density and anemia, but these findings also have many other causes. Guidelines recommend checking for other medical issues when symptoms are broad or severe, rather than starting treatment based on one low lab result 1, 2.

Mood, energy, and cognitive symptoms

• Fatigue or lower stamina
• Low motivation
• Depressed mood or irritability
• Trouble concentrating
• Poor sleep

These symptoms matter, but they are not specific to testosterone deficiency. Depression, obstructive sleep apnea, thyroid disease, anemia, chronic pain, overtraining, shift work, and alcohol can all look similar. That overlap is one reason the American Urological Association guideline recommends a careful workup before treatment 2.

Symptoms in boys and younger men

In boys, testosterone deficiency can delay puberty, slow growth of facial or body hair, reduce muscle development, or affect genital development. In younger adult men, infertility may be the first clue. Genetic conditions such as Klinefelter syndrome can cause primary hypogonadism and may be found during fertility testing 6.

What is one of the first signs of testosterone deficiency?

Low sex drive is often one of the first symptoms men notice, especially when it is new, persistent, and paired with fewer morning erections. In the European Male Ageing Study, sexual symptoms were more closely tied to low testosterone than general symptoms such as fatigue 3.

That does not mean every change in libido is low T. Stress, relationship strain, depression, poor sleep, alcohol, cannabis, some antidepressants, blood pressure medicines, and untreated diabetes can all lower sexual desire or erections. A good evaluation looks at the whole picture, not just one hormone.

What causes low testosterone in men?

Low testosterone can come from the testes, the brain’s hormone signals, or health factors that suppress the system. Clinicians often use luteinizing hormone, or LH, and follicle-stimulating hormone, or FSH, to sort this out. High LH and FSH suggest a testicular problem; low or normal LH and FSH suggest a brain-signal or functional cause 1, 2.

Primary hypogonadism: testicular causes

Primary hypogonadism means the testes cannot make enough testosterone even when the brain is sending a strong signal. Causes include Klinefelter syndrome, prior chemotherapy or radiation, testicular injury, undescended testes, mumps orchitis, and some autoimmune or genetic conditions 1, 6.

Secondary hypogonadism: pituitary or hypothalamus causes

Secondary hypogonadism means the hypothalamus or pituitary is not sending enough signal to the testes. Causes can include pituitary tumors, high prolactin, severe illness, head injury, iron overload, certain genetic conditions, and some medications. Opioids are a well-described cause of low testosterone through suppression of the hypothalamic-pituitary-gonadal axis 7.

Lifestyle and medication-related causes

Obesity and type 2 diabetes are common, partly reversible drivers of low testosterone. In men with type 2 diabetes, studies have found hypogonadotropic hypogonadism, meaning low testosterone with low or inappropriately normal LH and FSH, more often than expected 4.

Sleep also matters. Obstructive sleep apnea is linked with lower testosterone and sexual symptoms, and TRT can worsen untreated severe sleep apnea in some men, which is why guidelines list untreated severe obstructive sleep apnea as a reason not to start TRT 1, 5.

How is low testosterone diagnosed?

Diagnosis usually requires 2 separate morning tests plus symptoms that fit. The Endocrine Society and American Urological Association both recommend confirming a low result because testosterone can vary from day to day and can be temporarily lowered by poor sleep, illness, intense calorie restriction, or medication changes 1, 2.

Morning blood tests and repeat testing

The American Urological Association uses a total testosterone level below 300 ng/dL as a reasonable cut-off to support the diagnosis in the right clinical setting, while still requiring symptoms and repeat morning testing 2. The Endocrine Society also recommends morning fasting total testosterone as the initial test, with repeat confirmation 1.

Total testosterone vs. free testosterone

Total testosterone measures testosterone in the blood, including testosterone bound to proteins. Free testosterone is the small amount not tightly bound. Sex hormone binding globulin, or SHBG, can change total testosterone results; obesity often lowers SHBG, while aging and some liver or thyroid conditions can raise it 1.

Free testosterone can help when total testosterone is near the lower limit or when SHBG is likely abnormal. Guidelines recommend using accurate assays or validated calculations because direct free-testosterone tests are not all equally reliable 1.

Ruling out other conditions

A clinician may check LH, FSH, prolactin, complete blood count, thyroid function, A1c, lipids, liver tests, and sometimes iron studies or pituitary imaging, depending on the pattern. The goal is to find whether low testosterone is primary, secondary, or functional and whether another condition is safer to address first 1, 2.

Can low testosterone go back to normal?

Low testosterone can improve when the cause is functional, such as obesity, untreated sleep apnea, heavy alcohol use, or certain medications. It is less likely to normalize on its own when the testes are damaged or when there is a fixed pituitary disorder. The honest answer depends on the cause.

Lifestyle changes that can help

Weight loss can raise testosterone in men with obesity. A systematic review and meta-analysis found that both diet-related weight loss and bariatric surgery were associated with increases in testosterone, with larger increases after greater weight loss 8. Individual results vary, and weight loss should be planned in a way that protects nutrition, muscle, sleep, and mental health.

• Treat possible sleep apnea, especially loud snoring, witnessed pauses in breathing, or morning headaches.
• Build resistance training and regular walking or cardio into the week.
• Reduce heavy alcohol use and avoid anabolic steroid use.
• Review medications with a clinician, especially opioids, glucocorticoids, and some psychiatric medicines.
• Address type 2 diabetes, insulin resistance, and waist circumference with a sustainable metabolic plan.

When medical treatment is considered

Medical treatment is usually considered when a man has persistent symptoms, confirmed low testosterone, and a cause that will not resolve with safer first steps. Men who want future fertility need special care because testosterone replacement therapy can suppress sperm production 1, 2.

What are the treatment options for confirmed testosterone deficiency?

Treatment depends on the cause, symptoms, fertility goals, and risks. Testosterone replacement therapy, or TRT, is one option for confirmed hypogonadism, but it is not the right path for every man. Fertility-preserving options may be considered by specialists in selected cases 1, 2.

Testosterone replacement therapy forms

TRT can be prescribed as gels, patches, injections, pellets, nasal products, or oral formulations depending on country, product, and clinical fit. FDA-approved testosterone labels warn that testosterone can increase hematocrit, may worsen sleep apnea, can cause acne or fluid retention, and may suppress sperm production 9.

The Testosterone Trials studied older men with low testosterone and symptoms; testosterone gel improved sexual activity and desire more than placebo, while effects on energy were smaller and less consistent 10. Trial results do not guarantee an individual outcome, and the study used a specific FDA-approved product under trial monitoring.

Fertility-preserving options

Men who want children should tell their clinician before starting any testosterone therapy. Exogenous testosterone can reduce LH and FSH signaling and lower sperm production. Specialists may consider fertility-preserving options such as human chorionic gonadotropin, or hCG, and sometimes clomiphene citrate in selected men, but these require clinician oversight and monitoring 1, 2.

Risks and who should not use TRT

Guidelines recommend avoiding TRT in men with prostate cancer or breast cancer, elevated hematocrit, untreated severe obstructive sleep apnea, severe lower urinary tract symptoms, uncontrolled heart failure, recent heart attack or stroke, thrombophilia, or men planning fertility in the near term 1.

Where do GLP-1s and longevity peptides fit in with low testosterone?

GLP-1 medications do not replace TRT, and longevity peptides are not testosterone therapy. Their role is different: they may support upstream health factors, such as body weight or metabolic health, that can be linked with low testosterone in some men. Chia’s role is in this adjacent metabolic and longevity space, not in prescribing testosterone.

At Chia, we offer compounded tirzepatide tablets and injections and compounded semaglutide injections for eligible patients seeking weight-loss treatment. The active ingredients semaglutide and tirzepatide have been studied for chronic weight management in large clinical trials, with gastrointestinal side effects such as nausea, vomiting, diarrhea, and constipation among the most common; compounded formulations are not FDA-approved and do not have FDA-evaluated outcomes data 11, 12.

We also offer sermorelin, a growth-hormone-releasing peptide, in injection, nasal spray, and tablet forms. Sermorelin is separate from testosterone. It should not be described as TRT, and it is not a treatment for male hypogonadism.

Chia care is 100% online. Patients complete a short health questionnaire, then a licensed US provider reviews it and prescribes only where clinically appropriate. Dosing is provider-guided and adjusted over time, including microdosing plans where listed, and medications are compounded by state-licensed US 503A pharmacies and shipped to the patient’s door.

When should you talk to a clinician about low testosterone symptoms?

Talk to a clinician if low libido, fewer morning erections, erectile changes, fatigue, depressed mood, infertility, or loss of strength lasts more than a few weeks or affects your quality of life. Seek care sooner if symptoms are sudden, severe, or paired with headaches, vision changes, testicular pain, breast discharge, or unexplained weight loss.

It is also worth getting evaluated if you have obesity, type 2 diabetes, obstructive sleep apnea, chronic opioid use, prior testicular injury, chemotherapy, radiation, or a history of delayed puberty. These details help a clinician decide which labs to order and whether referral to urology, endocrinology, sleep medicine, or fertility care makes sense 1, 2.

1. 1Write down your main symptoms and when they started.
2. 2List medications, supplements, alcohol, cannabis, and opioid use honestly.
3. 3Ask about morning total testosterone testing and whether repeat testing is needed.
4. 4Discuss fertility goals before any hormone treatment.
5. 5Ask whether sleep apnea, thyroid disease, anemia, diabetes, depression, or medication effects should be checked.

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