Skip to content
ClinCalc Pro
Menu
Calculators Drugs Pathways AI Dx Donate Get the App
Mixed testosterone esters Pregnancy: Contraindicated in women who are pregnant. There are no adequate data for use in pregnant women and, in view of the risk of virilisation of the foetus, Sustanon 250 should not be used during pregnancy; treatment should be discontinued when pregnancy occurs. There are no adequate data for use during lactation, and it should not be used while breast-feeding. Fertility: in men, treatment with androgens can lead to fertility disorders by repressing sperm formation; in women, it can lead to an infrequent or repressed menstrual cycle. (§4.6, complete in the bundle.)

Testosterone decanoate, isocaproate, phenylpropionate and propionate

Brand names: Sustanon 250

This is a combination of four testosterone esters formulated as an oily intramuscular injection used for testosterone replacement in men with hypogonadism. The mix of short- and longer-acting esters provides a sustained androgenic effect from a single injection.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Testosterone (androgen) replacement — adults, including the elderly: usually, one injection of 1 mL every 3 weeks is adequate. Sustanon 250 is a 250 mg/mL solution, so 1 mL is one 250 mg ampoule. §4.2 opens: 'In general, the dose should be adjusted to the response of the individual patient', and §4.4 adds that clinicians should adjust the dosage individually to ensure maintenance of eugonadal testosterone levels. A SECOND POPULATION in the same §4.2, quoted verbatim: 'Female-to-male transsexuals: Different specialist centres have used doses varying from one injection of 1ml every two weeks to one injection of 1ml every four weeks.' — note the label frames this as observed specialist-centre practice, not as a fixed recommendation.
Route: Deep intramuscular injection. §4.2 Method of administration, verbatim: 'Sustanon 250 should be administered by deep intramuscular injection.'
Frequency: One injection of 1 mL every 3 weeks in adults, adjusted to the response of the individual patient. For female-to-male transsexuals the label reports specialist-centre intervals ranging from one injection of 1 mL every two weeks to one injection of 1 mL every four weeks.
NO MAXIMUM DOSE IS RECORDED because the label states none for this indication — §4.2 sets no ceiling and instead directs that the dose be titrated to the individual patient's response and to eugonadal testosterone levels. No ceiling has been imported from any other product or route. || The dose is quoted in MILLILITRES because that is how the label expresses it; the 250 mg figure is the licensed product strength (250 mg/ml) named in the product title, not a separate dosing statement. || PAEDIATRIC: §4.2, verbatim — 'Safety and efficacy have not been adequately determined in children and adolescents. Pre-pubertal children treated with Sustanon 250 should be treated with caution (see section 4.4).' There is no paediatric posology in this label, so paedDose is null and nothing has been scaled from the adult dose. §4.8 records that precocious sexual development, an increased frequency of erections, phallic enlargement and premature epiphyseal closure have been reported in prepubertal children using androgens. || WOMEN: §4.8 states that treatment may induce signs of virilisation — hoarseness, acne, hirsutism, menstrual irregularity and alopecia. || §4.4 ends at the source-fetch truncation marker, so the warnings list is PARTIAL. || Side effects cannot be quickly reversed by discontinuing medication, because of the nature of the depot esters.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Pregnancy
  • Known or suspected carcinoma of the prostate or breast
  • Breast-feeding
  • Hypersensitivity to the active substance or to any of the excipients listed in section 6.1, including arachis oil (refined) — Sustanon 250 is therefore contraindicated in patients allergic to peanuts or soya
  • PROVENANCE: §4.3 of the Sustanon 250 SPC, complete in the bundle.

Side effects

  • Common: weight increased
  • Common: haematocrit increased
  • Rare: pulmonary oil microembolism — microembolism of oily solutions can in rare cases cause cough, dyspnoea, malaise, hyperhydrosis, chest pain, dizziness, paraesthesia or syncope, occurring during or immediately after the injection and reversible
  • Frequency not known: prostatic cancer (progression of a sub-clinical prostatic cancer)
  • Frequency not known: polycythaemia
  • Frequency not known: fluid retention
  • Frequency not known: depression, nervousness, mood altered, libido increased, libido decreased
  • Frequency not known: hypertension
  • Frequency not known: nausea
  • Frequency not known: hepatic function abnormal
  • Frequency not known: pruritus, acne
  • Frequency not known: myalgia
  • Frequency not known: ejaculation disorder, gynaecomastia, oligospermia, priapism, benign prostatic hyperplasia (prostatic growth to the eugonadal state)
  • Frequency not known: abnormal lipids (a decrease in serum LDL-C, HDL-C and triglycerides), PSA increased, red blood cell count increased, haemoglobin increased
  • Injectables in general may cause a local reaction at the injection site
  • In women: signs of virilisation, which may include hoarseness, acne, hirsutism, menstrual irregularity and alopecia
  • In prepubertal children using androgens: precocious sexual development, an increased frequency of erections, phallic enlargement, premature epiphyseal closure
  • Because of the nature of the product, side effects cannot be quickly reversed by discontinuing medication
  • PROVENANCE: §4.8 of the Sustanon 250 SPC, complete in the bundle; the label notes these reactions are those associated with androgen therapy in general.

Monitoring

  • Testosterone level at baseline and at regular intervals during treatment — adjust the dosage individually to maintain eugonadal testosterone levels
  • Digital rectal examination of the prostate and PSA, to exclude benign prostatic hyperplasia or a sub-clinical prostate cancer — before the start of treatment, at quarterly intervals for the first 12 months, and yearly thereafter
  • Haematocrit and haemoglobin, to exclude polycythaemia — on the same before/quarterly-for-12-months/yearly schedule
  • On long-term androgen therapy, also monitor haemoglobin, haematocrit, liver function tests and lipid profile regularly
  • Blood pressure — testosterone may cause a rise in blood pressure; use with caution in men with hypertension
  • Hypercalcaemia or hypercalciuria in patients with mammary carcinoma, hypernephroma, bronchial carcinoma or skeletal metastases; treat the calcium disturbance first and resume hormone therapy only after normal calcium levels are restored
  • STOP TREATMENT IMMEDIATELY if a patient with severe cardiac, hepatic or renal insufficiency or ischaemic heart disease develops oedema with or without congestive cardiac failure; monitor patients who have had myocardial infarction, cardiac/hepatic/renal insufficiency, hypertension, epilepsy or migraine for deterioration or recurrence, and stop treatment immediately in such cases
  • Caution in epilepsy or migraine (or a history of either) — androgens may occasionally induce fluid and sodium retention
  • Diabetes mellitus — androgens in general and Sustanon 250 can improve glucose tolerance in diabetic patients
  • Anticoagulant therapy — androgens can enhance the anticoagulant action of coumarin-type agents
  • Sleep apnoea — testosterone can cause or exacerbate pre-existing sleep apnoea; apply caution and good clinical judgment in patients with risk factors such as adiposity or chronic lung disease
  • CAVEAT: §4.4 ends at the source-fetch truncation marker, so this is not the label's complete set of warnings and precautions.

Clinical monograph

How it works

After intramuscular injection the esters are gradually hydrolysed to release testosterone, the principal endogenous androgen, which acts on androgen receptors to maintain male secondary sexual characteristics, libido, muscle and bone, and to support spermatogenesis.

Prescribing in practice

  • It is contraindicated in known or suspected prostate or breast carcinoma in men, and prostate assessment (including PSA where appropriate) and haematocrit should be checked before starting, as androgens can stimulate existing prostate cancer.
  • Polycythaemia can develop, so the haematocrit should be monitored periodically during therapy.
  • It should be avoided in pregnancy because of the risk of virilisation of a female foetus, and the oily injection must be given by deep intramuscular injection.

Monitoring

Monitor serum testosterone to guide dosing interval, together with haematocrit, prostate status and PSA, lipids, and liver function during long-term replacement.

Counselling the patient

  • This treatment is given as a deep injection into a muscle by a healthcare professional.
  • Report difficulty passing urine, breast tenderness or swelling, or persistent headache.
  • Mood, libido, and energy may take some weeks to stabilise after starting.

Evidence & guidelines

Use is supported by long-standing clinical experience and endocrine society guidance on testosterone replacement in confirmed male hypogonadism.

Reference: UK Endocrine Society; Confirm identity and dosing against the manufacturer SPC (eMC) and NICE. 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.

Calculators
Pathways