Testosterone deficiency (hypogonadism)

Testosterone deficiency is present when repeatedly low blood testosterone levels are measured together with typical complaints such as lack of drive, loss of libido or muscle loss. The diagnosis is based on standardised laboratory testing, not on individual symptoms. In a video consultation your complaints can be assessed in a structured way, laboratory tests can be arranged, and treatment can be supervised subject to medical assessment.

Medically reviewed by Adi Zoabi, Approbation als Arzt.
Last reviewed on August 31, 2026. Updated as clinical guidelines change.

Overview

Testosterone is the most important male sex hormone. It influences muscle, bone density, blood formation, metabolism, mood and sexual function. Doctors speak of testosterone deficiency (hypogonadism) when repeatedly low blood testosterone levels are measured together with matching complaints – such as lack of drive, loss of libido or erectile dysfunction. From middle age onwards testosterone levels decline slowly; however, a deficiency requiring treatment is not a normal sign of ageing but a diagnosis in its own right. The work-up is laboratory-based: at least two morning blood samples on different days are decisive, because testosterone levels fluctuate considerably during the day. In a video consultation your complaints can be assessed in a structured way, suitable laboratory tests can be arranged and the results discussed in detail. Subject to medical assessment, treatment can then be initiated and supervised – from targeted lifestyle measures to testosterone replacement therapy with regular follow-up monitoring. Any necessary physical examinations are arranged in person where required.

Common causes

Testosterone deficiency can have many causes. The most frequent is so-called functional hypogonadism: obesity, type 2 diabetes, metabolic syndrome, chronic sleep deprivation or untreated sleep apnoea suppress the body's own testosterone production. Chronic illnesses, pronounced stress, regular alcohol consumption and certain medications – such as opioids or corticosteroid preparations – can also lower hormone levels. Less commonly the cause lies directly in the testicles (primary hypogonadism), for example after injuries, infections or chemotherapy, or in genetic conditions such as Klinefelter syndrome. In secondary hypogonadism the hormonal control by the pituitary gland or hypothalamus is disturbed, for instance by benign tumours or an elevated prolactin level. Previous use of anabolic steroids is also a relevant and often overlooked cause. The distinction is made using laboratory values such as LH, FSH and prolactin and determines the further diagnostic and therapeutic approach.

When to see a doctor

Seek medical evaluation if complaints such as persistent exhaustion, loss of libido, erectile dysfunction, unintended muscle loss or low mood persist for several weeks and affect your daily life. Early laboratory diagnostics prevent unspecific symptoms from remaining unrecognised for years or being treated prematurely without a confirmed diagnosis. Specific warning signs that should be examined promptly – preferably in person – include: palpable lumps, hardening or swelling of the testicles, newly developed breast tissue growth, new visual disturbances or unusually severe headaches, and an unfulfilled wish to have children. A structured work-up is also advisable if you have used anabolic steroids in the past. If you notice signs of a medical emergency – such as sudden chest pain, shortness of breath, paralysis, speech disturbances or impaired consciousness, as can occur with a heart attack or stroke – call the emergency number 112 immediately.

Symptoms & Indications

Persistent tiredness and lack of drive Reduced sexual desire (loss of libido) Erectile dysfunction Loss of muscle mass and strength Increase in abdominal fat despite an unchanged lifestyle Low mood and irritability Impaired concentration and memory Reduced beard growth or diminished body hair

Treatment Options

Laboratory-based diagnostics with at least two morning testosterone measurements on different days
Extended hormone testing (including LH, FSH, prolactin, SHBG) to clarify the cause
Treatment of contributing underlying conditions such as obesity, type 2 diabetes or sleep apnoea
Lifestyle measures: weight reduction, resistance training, sleep hygiene, reduced alcohol intake
Subject to medical assessment: testosterone replacement therapy (androgens), e.g. as a gel or injection
Regular follow-up monitoring during replacement therapy (including testosterone level, haematocrit, PSA)
Counselling on fertility and family planning before starting replacement therapy

Important Notes

Testosterone replacement therapy is only started after confirmed laboratory diagnostics and medical assessment – a prescription cannot be guaranteed. Telemedicine cannot replace the physical examination (e.g. palpation of the prostate and testicles), which will be arranged in person where required.
Regular laboratory monitoring is medically necessary during replacement therapy. In cases of active prostate cancer, unclear testicular findings or a current wish to have children, testosterone therapy is generally not suitable and requires specialist evaluation.
Palpable lumps or swelling of the testicles, new visual disturbances or severe headaches should be examined in person by a doctor promptly.
If you notice signs of a medical emergency – such as sudden chest pain, shortness of breath, paralysis or speech disturbances – call the emergency number 112 immediately.

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Medical notice: Not a substitute for an in-person medical examination. The information on this page is intended for general guidance only. In an emergency, please call 112.

Frequently Asked Questions

How is testosterone deficiency diagnosed?

The basis is at least two morning blood samples taken on different days, because testosterone levels fluctuate considerably during the day. Depending on the findings, additional values such as LH, FSH, prolactin and SHBG are measured to narrow down the cause. Only the combination of repeatedly low levels and matching complaints justifies the diagnosis.

Can I receive testosterone replacement therapy via the video consultation?

In the video consultation your complaints and laboratory results are evaluated by a doctor. Subject to medical assessment, testosterone replacement therapy can be initiated and prescribed via private prescription if the diagnosis is confirmed and there are no contraindications. A prescription cannot be promised; any necessary in-person examinations or check-ups will be arranged where required.

What does the treatment cost and will my private health insurance cover it?

Billing is carried out as a private medical service according to the German medical fee schedule (GOÄ); you receive a transparent invoice. Privately insured patients can usually submit this to their insurer; reimbursement depends on your individual plan. Self-payers see the costs before booking; laboratory tests and medication are billed separately.

Can I improve my testosterone level without medication?

Yes, in many cases this is possible. Weight reduction, regular resistance training, sufficient sleep, treatment of sleep apnoea and reduced alcohol intake can measurably support the body's own testosterone production. Whether this is sufficient depends on the cause and is assessed through follow-up testing.

What are the risks of testosterone replacement therapy?

During replacement therapy the haematocrit may rise, the body's own hormone production and fertility may be suppressed, and skin changes may occur. This is why careful evaluation before starting and regular laboratory monitoring during treatment are necessary. Subject to medical assessment, treatment is only continued if benefit and tolerability are confirmed.