What is Testosterone Replacement Therapy?
Testosterone Replacement Therapy (TRT) refers to the medical treatment of male hypogonadism — a clinical condition characterised by the failure of the testes to produce adequate testosterone, resulting in symptoms that significantly affect quality of life. TRT is approved by the European Medicines Agency (EMA) for the treatment of hypogonadism in adult men when testosterone deficiency has been confirmed by both clinical symptoms and repeated laboratory testing.
TRT involves supplementing the body’s testosterone levels with exogenous (externally produced) testosterone in a variety of EMA-approved formulations. It is not a treatment for age-related testosterone decline in otherwise healthy men without confirmed hypogonadism.
How does Testosterone work in the body?
Testosterone is the primary male sex hormone (androgen), produced predominantly in the Leydig cells of the testes under the regulation of luteinising hormone (LH) from the pituitary gland. It plays essential roles throughout the body:
- Sexual function: Maintains libido, supports erectile function, and drives sexual development during puberty
- Muscle and bone: Promotes muscle protein synthesis and bone mineral density maintenance
- Red blood cell production: Stimulates erythropoietin production in the kidneys, supporting red blood cell formation
- Energy and mood: Influences energy levels, mood, cognitive function, and overall sense of well-being
- Body composition: Influences the distribution of fat and lean muscle mass
- Spermatogenesis: Supports (but does not solely drive) sperm production — this is also regulated by FSH and intratesticular testosterone levels
In hypogonadism, inadequate testosterone production leads to a characteristic cluster of symptoms. TRT replaces the deficit, restoring physiological testosterone levels and alleviating symptoms.
Who is TRT for?
TRT is indicated for adult men with documented hypogonadism, defined as:
- Clinical symptoms consistent with low testosterone: reduced libido, erectile dysfunction, fatigue, decreased muscle mass, increased body fat, mood disturbance, poor concentration, reduced body/facial hair, or reduced bone density, AND
- Biochemically confirmed low testosterone: Two separate morning serum total testosterone measurements below the laboratory reference range (typically <12 nmol/L or <300 ng/dL, but reference ranges vary by laboratory and assay)
Types of hypogonadism:
- Primary hypogonadism (testicular failure): Caused by conditions such as Klinefelter syndrome, testicular injury, mumps orchitis, chemotherapy
- Secondary hypogonadism (hypothalamic-pituitary failure): Caused by conditions such as pituitary tumours, haemochromatosis, hyperprolactinaemia, or Kallmann syndrome
TRT is not indicated for:
- Age-related decline in testosterone without confirmed hypogonadism
- Men with prostate cancer or breast cancer
- Men with polycythaemia (significantly elevated red blood cell count)
- Men with severe untreated obstructive sleep apnoea
- Men who wish to father children in the near term (without specialist co-management)
TRT Formulations and Dosage
| Formulation | Examples | Frequency | Dose |
|---|---|---|---|
| Transdermal gel | Testogel, Testim, AndroGel | Daily | 25–75 mg/day |
| Long-acting injection | Nebido (testosterone undecanoate) | Every 10–14 weeks | 1000 mg |
| Short-acting injection | Testosterone enanthate / cypionate | Every 2–4 weeks | 100–250 mg |
| Buccal tablet | Striant | Twice daily | 30 mg |
The prescribing doctor will select the most appropriate formulation based on patient preference, lifestyle, compliance, and clinical considerations.
Transdermal gels: Applied daily to clean, dry skin (shoulders, upper arms, or abdomen — not the genitals). Allow to dry before dressing. Wash hands after application. Avoid skin-to-skin contact with the application site with women, children, or pregnant women until the gel has dried.
Nebido (long-acting injection): Given by a healthcare professional as an intramuscular injection every 10–14 weeks. Provides stable testosterone levels without daily application.
Efectos secundarios
Efectos secundarios frecuentes
- Acne or oily skin
- Increased red blood cell count (polycythaemia) — monitored via regular blood tests
- Fluid retention (mild oedema)
- Prostate-specific antigen (PSA) increase — monitoring required
- Increased libido (particularly early in treatment)
- Mood changes
Efectos secundarios poco frecuentes
- Sleep apnoea (may worsen pre-existing sleep apnoea)
- Gynaecomastia (breast tissue development — related to testosterone aromatisation to oestradiol)
- Male pattern hair loss (in genetically predisposed men)
- Testicular atrophy (due to suppression of natural testosterone production and LH)
- Skin reactions at the application site (gels) or injection site
Serious concerns requiring monitoring
- Cardiovascular risk: The relationship between TRT and cardiovascular events is complex and remains an area of ongoing research. Men with pre-existing cardiovascular disease should discuss the risk-benefit profile with their doctor.
- Polycythaemia: Excess red blood cell production increases thrombosis risk — haematocrit must be monitored
- Prostate health: TRT may stimulate prostate tissue growth; PSA must be monitored. TRT is contraindicated in men with prostate cancer.
Monitoring during TRT
Regular medical monitoring is essential throughout TRT. A doctor will typically assess:
| Parameter | Frequency |
|---|---|
| Serum testosterone | 3 months, then annually |
| Full blood count (haematocrit) | 3 months, then annually |
| PSA (prostate-specific antigen) | Annually (or more frequently in older men) |
| Liver function | Annually |
| Lipid profile | Annually |
| Digital rectal examination | As clinically indicated |
How to access TRT online in Europe
Testosterone is a prescription-only medicine (POM) and a controlled substance in most EU member states. No puede dispensarse legalmente sin una receta válida de un profesional médico autorizado.
Prescrivia operates as a technology intermediary: we do not prescribe medicines, employ doctors, or sell medicines. Our platform connects patients with independent EU-registered doctors who can conduct confidential online consultations.
Important note on TRT assessment: Diagnosing hypogonadism requires blood testing to confirm low testosterone levels. An online assessment is a first step — the doctor may refer you for blood tests and will review the results before any prescribing decision is made.
El proceso:
- Complete una evaluación de salud: Describe your symptoms, relevant medical history, and any previous testosterone testing or treatment.
- Doctor review and blood test referral: An independent EU-registered doctor reviews your assessment. If clinically indicated, they will refer you for appropriate blood tests.
- Results review and prescription: If test results confirm hypogonadism and TRT is appropriate, the doctor may issue a prescription.
- Pharmacy fulfilment: The prescription is sent to a licensed EU pharmacy partner para su dispensación y entrega directa.
Importante: Prescrivia does not guarantee that a prescription will be issued. All prescribing decisions are made independently by qualified medical professionals based on confirmed clinical and biochemical criteria.
Información importante de seguridad
TRT is contraindicated in men who:
- Have prostate cancer or breast cancer
- Have polycythaemia (significantly raised haematocrit)
- Have severe untreated heart failure
- Have uncontrolled severe sleep apnoea
- Are allergic to testosterone or any excipient in the formulation
Informe a su médico si:
- Are using TRT and experience chest pain, breathlessness, leg swelling, or symptoms of stroke
- Are taking anticoagulants such as warfarin (testosterone can potentiate anticoagulant effect)
- Are taking insulin or other antidiabetic medicines (testosterone may improve insulin sensitivity — blood glucose monitoring may need adjustment)
- Have or have had liver tumours
TRT is not the same as anabolic steroid misuse: TRT restores physiological testosterone levels to within the normal range. It is not the same as supraphysiological doses of testosterone or anabolic steroids used without medical supervision, which carry substantially greater health risks.
Fuentes
La información médica de esta página se basa en las siguientes fuentes:
- European Medicines Agency (EMA). Testogel (testosterone) — Summary of Product Characteristics. Disponible en: ema.europa.eu
- European Association of Urology (EAU). Guidelines on Male Hypogonadism. 2023. uroweb.org
- World Health Organization (WHO). Testosterone — Essential Medicines information. who.int
- Bhasin S, et al. Testosterone Therapy in Men with Hypogonadism: An Endocrine Society Clinical Practice Guideline. Journal of Clinical Endocrinology & Metabolism. 2018.
Este contenido se revisa periódicamente para reflejar las directrices clínicas actualizadas. Se proporciona únicamente con fines informativos y no constituye asesoramiento médico. Consulte siempre a un profesional sanitario cualificado para obtener asesoramiento relevante para sus circunstancias de salud individuales.
Frequently asked questions
- What is Testosterone Replacement Therapy used for?
- Testosterone Replacement Therapy (TRT) is prescribed for male hypogonadism — a condition where the testes do not produce sufficient testosterone. Symptoms of low testosterone (low T) include reduced libido, erectile dysfunction, fatigue, reduced muscle mass, mood changes, and impaired concentration. TRT is only prescribed after blood tests confirm clinically low testosterone levels alongside appropriate symptoms.
- What are the different types of TRT available?
- Testosterone replacement is available in several formulations approved by the EMA: transdermal gels (applied daily to skin — Testogel, AndroGel, Testim), injectable testosterone (long-acting injections such as Nebido/testosterone undecanoate every 10–14 weeks, or shorter-acting testosterone esters every 2–4 weeks), and buccal tablets (applied to the gum). The appropriate formulation is determined by a doctor based on the patient's preference, lifestyle, and clinical circumstances.
- Can TRT affect fertility?
- Yes. Exogenous testosterone suppresses the body's natural hormonal signals (LH and FSH) that stimulate sperm production. Men who wish to preserve or maintain fertility should discuss this with their doctor before starting TRT. Alternative treatments such as human chorionic gonadotropin (hCG) or selective oestrogen receptor modulators (SERMs) may be considered for men with hypogonadism who wish to maintain fertility.
- How quickly does TRT improve symptoms?
- The timeline varies by symptom and individual. Sexual function and libido may improve within a few weeks. Energy, mood, and cognitive function often improve over 3–6 months. Muscle mass and body composition changes may take 6–12 months to become apparent. Bone density improvements require treatment over 1–2 years. Regular monitoring by a doctor is essential throughout treatment.
- Can I get TRT online in Europe?
- TRT is a prescription-only medicine in all EU member states and requires confirmed diagnosis of hypogonadism via blood testing before a prescription can be issued. Puede acceder a TRT evaluation a través de plataformas intermediarias en línea que le conectan con médicos independientes registrados en la UE. The doctor will review your symptoms and, if appropriate, refer you for relevant blood tests before any prescribing decision is made.
Prescrivia es únicamente una plataforma intermediaria. No prestamos servicios médicos, no prescribimos tratamientos ni dispensamos medicamentos. Todas las decisiones médicas son tomadas por médicos independientes registrados en la UE. Todos los medicamentos son dispensados por farmacias autorizadas de la UE. Esta plataforma facilita la conexión entre pacientes y profesionales sanitarios.