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Androgen (Male Sex Hormone) Pregnancy: Contraindicated for women — virilisation of female fetus if inadvertent exposure

Testosterone (Replacement)

Brand names: Testogel, Nebido (IM), Testim gel, Tostran gel

Adult dose

Dose: Gel (Testogel 50 mg): 1–2 sachets OD on skin. Depot IM (Nebido 1000 mg/4 mL): 1000 mg IM every 10–14 weeks after loading at 6 weeks.
Route: Transdermal gel or IM injection
Frequency: Daily (gel) or every 10–14 weeks (depot IM)
Max: 100 mg/day (gel); 1000 mg per 10 weeks (depot)
For hypogonadism. Gel: apply to shoulders/upper arms/abdomen — not genitals. Wash hands; cover skin. Risk of transfer to women/children. Nebido: dose interval adjusted to trough testosterone levels.

Paediatric dose

Route: IM injection
Frequency: Monthly
Max: Individualised under specialist supervision
Concentration: 250 mg/mL (Sustanon) for pubertal induction mg/ml
Delayed puberty/hypogonadism in boys: Sustanon 25–50 mg IM monthly, increasing slowly. Specialist paediatric endocrinology only. Bone age monitoring essential.

Dose adjustments

Renal

No dose adjustment required

Hepatic

Oral testosterone formulations (17-alpha-alkylated) avoided due to hepatotoxicity; transdermal/IM have minimal hepatic effects

Clinical pearls

  • Gel transfer: patient must wash hands, cover application site until dry — risk to pregnant partners and children (virilisation)
  • Fertility: exogenous testosterone suppresses spermatogenesis — if fertility desired, use hCG-based therapy instead
  • Polycythaemia: check haematocrit 3–6 months after starting and annually — stop if haematocrit >0.54
  • PSA monitoring: check at baseline, 3–6 months, then annually; refer if PSA rises >1.4 ng/mL above baseline in 12 months

Contraindications

  • Prostate cancer or breast cancer in men
  • Hypercalcaemia
  • Polycythaemia
  • Severe sleep apnoea

Side effects

  • Polycythaemia (check haematocrit)
  • Acne
  • Oily skin
  • Hair loss (androgenic alopecia)
  • Prostate enlargement/PSA rise
  • Sleep apnoea exacerbation
  • Testicular atrophy (endogenous LH/FSH suppressed)
  • Skin transfer to partners/children

Interactions

  • Anticoagulants (warfarin) — testosterone enhances anticoagulant effect; monitor INR
  • Insulin — testosterone may improve insulin sensitivity
  • Corticosteroids — sodium retention, oedema risk

Monitoring

  • Testosterone level (trough for IM; 2–4h post-application for gel)
  • Haematocrit/haemoglobin (3-monthly for first year)
  • PSA (baseline, 3–6 months, then annually)
  • DRE and prostate assessment
  • Bone mineral density (osteoporosis risk in hypogonadism)
  • Mood and libido

Reference: BNFc; BNF; European Association of Urology (EAU) Guidelines on Male Hypogonadism 2022. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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