Testosterone (Replacement)
Brand names: Testogel, Nebido (IM), Testim gel, Tostran gel
Testosterone replacement is used for confirmed male hypogonadism only. It is not appropriate for age-related symptoms in the absence of biochemical hypogonadism.
Adult dose
Dose adjustments
UK SPC §4.2: 'Patient suffering from severe renal or hepatic insufficiency Please see section 4.4.' §4.4: 'In patients suffering from severe cardiac, hepatic or renal insufficiency, or ischaemic disease, treatment with testosterone may cause severe complications characterised by oedema with or without congestive cardiac failure. In such case, treatment must be stopped immediately. In addition, diuretic therapy may be required.' No dose figure is given.
UK SPC §4.2 refers severe hepatic insufficiency to §4.4: treatment with testosterone may cause severe complications characterised by oedema with or without congestive cardiac failure; in such case treatment must be stopped immediately and diuretic therapy may be required. Liver function tests should be monitored in long-term androgen therapy. No dose figure is given.
Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via MHRA Products — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.
US labelling (FDA)
Reference — US labelling, may differ from UKDOSAGE AND ADMINISTRATION Prior to initiating, TESTOPEL ® (testosterone pellets) confirm the diagnosis of hypogonadism by ensuring that serum testosterone concentrations have been measured in the morning on at least two separate days and that these serum testosterone concentrations are below the normal range. The suggested dosage for androgens varies depending on the age, and diagnosis of the individual patient. Dosage is adjusted according to the patient’s response and the appearance of adverse reactions. The dosage guideline for the testosterone pellets for replacement therapy in androgen-deficient males is 150mg to 450mg subcutaneously every 3 to 6 months. Various dosage regimens have …
Source: US FDA prescribing information (openFDA / DailyMed), label dated 2025-07-17. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.
Contraindications
- Hypersensitivity to the active substance or any of the excipients (§4.3)
- Known or suspected prostate cancer or breast carcinoma (§4.3)
Side effects
- Most frequent: skin reactions at the application site (erythema, acne, dry skin), anxiety and asthenia (§4.8)
- Skin-to-skin transfer to other persons can cause inadvertent androgenisation (e.g. facial/body hair growth, voice deepening, menstrual irregularities in women, premature puberty and genital enlargement in children) (§4.4)
- Weight gain; electrolyte changes (retention of sodium, chloride, potassium, calcium, inorganic phosphate and water) during high dose and/or prolonged treatment (§4.8)
- Mood disorders and emotional symptoms; nervousness, depression, hostility (§4.8)
- Hypertension; hot flushes/flushing; phlebitis (§4.8); thromboembolic events reported post-marketing (§4.4)
- Sleep apnoea (§4.8, §4.4)
- Gynaecomastia; increased frequency of erections, priapism, testicular pain, nipple disorder, prostate abnormalities; high-dose therapy commonly reversibly interrupts or reduces spermatogenesis, reducing the size of the testicles (§4.8)
- Oedema; hypersensitivity reactions (§4.8)
- Prostate cancer and hepatic neoplasm are listed as neoplasms (§4.8)
- This side-effect list may be incomplete — check the full SPC.
Interactions
- Oral anticoagulants: changes in anticoagulant activity (increased effect); increased monitoring of prothrombin time and INR, especially when androgens are started or stopped (§4.5)
- ACTH or corticosteroids: increased risk of developing oedema; give cautiously in cardiac, renal or hepatic disease (§4.5)
- Antidiabetic medication: insulin sensitivity and glycaemic control change with androgens; dose reduction might be needed (§4.5, §4.4)
- Laboratory tests: androgens may decrease thyroxine-binding globulin, decreasing total T4 and increasing resin uptake of T3 and T4; free thyroid hormone levels remain unchanged (§4.5)
Monitoring
- Morning pre-dose blood testosterone after steady state (usually reached by the second day) and periodically thereafter (§4.2)
- Prostate gland and breast: digital rectal examination and serum PSA at least once yearly, and twice yearly in elderly and at-risk patients (§4.4)
- Haemoglobin and haematocrit (polycythaemia), liver function tests and lipid profile in long-term therapy (§4.4)
- Blood calcium in cancer patients at risk of hypercalcaemia from bone metastases (§4.4)
- Glucose and HbA1c (§4.4)
- Signs of excessive androgen exposure (irritability, nervousness, weight gain, prolonged or frequent erections) requiring dosage adjustment (§4.4)
- Severe application-site reaction: re-evaluate treatment (§4.4)
Clinical monograph
How it works
It replaces endogenous testosterone, acting on androgen receptors to restore male secondary sexual characteristics and physiological androgen effects.
Prescribing in practice
- Confirm low morning testosterone on more than one occasion before starting; it is contraindicated in prostate or male breast cancer.
- Monitor haematocrit because of the risk of polycythaemia.
- Assess prostate status and PSA before and during treatment.
Monitoring
Monitor testosterone levels, haematocrit and prostate health (including PSA), with clinical review of response and adverse effects.
Counselling the patient
- This treatment is for a diagnosed testosterone deficiency, not for normal ageing.
- Attend for blood tests to check your red cell count and prostate marker.
- Report difficulty passing urine or other prostate symptoms.
Evidence & guidelines
Indicated for biochemically confirmed male hypogonadism per the SPC and specialist guidance.
Reference: European Association of Urology (EAU) Guidelines on Male Hypogonadism 2022; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).
Related
Curated clinical cross-links plus same-class fallbacks.
- Weight-Based Levothyroxine Dose Calculator · Thyroid
- Cryoprecipitate Dose Calculator for Fibrinogen Replacement · Transfusion Medicine
- Free Water Deficit in Hypernatraemia · Fluid / Electrolytes
- Potassium Deficit Calculator · Electrolytes
- Indications for Renal Replacement Therapy (RRT) in AKI · Treatment Decision
- Diabetic Ketoacidosis (DKA) · JBDS 2013 / Joint British Diabetes Societies; NICE NG17
- Adult Hypoglycaemia (Treated Diabetes) · JBDS-IP (2023): Hospital Management of Hypoglycaemia
- Adrenal Crisis · Society for Endocrinology Emergency Guidance (2024)
- Type 2 Diabetes Management · NICE NG28 2022
- Hyperthyroidism Management · BTA / ETA 2018
- Adrenal Insufficiency · Society of Endocrinology / ESE 2016