Synopsis
Confirm symptomatic testosterone deficiency with reliable repeated measurements, separate primary from hypothalamic-pituitary causes, and restore health without suppressing desired fertility or overlooking pituitary and testicular disease.
- Male hypogonadism requires compatible symptoms or signs plus consistently low testosterone; a single result in an asymptomatic or acutely unwell person is not the diagnosis.
- Obtain testosterone on two separate early-morning samples under appropriate fasting and stable-health conditions, using the local assay and reference range.
- Sex hormone-binding globulin alters total testosterone interpretation in obesity, liver disease, thyroid disease and some medicines; calculated free testosterone can help in borderline or discordant cases.
Key red flags
Headache, visual field loss, diplopia, galactorrhoea, polyuria, adrenal or thyroid deficit and severe central biochemistry needs prompt pituitary investigation.
Investigation priorities
Confirm persistent biochemical deficiency under standardised conditions.
Management branches
Compatible sexual, reproductive, pubertal or skeletal features and an initial low result.
- Review timing, fasting, acute illness, sleep, alcohol, obesity, medicines, opioid or anabolic exposure and repeat an early-morning total testosterone under standardised stable conditions.
- Add SHBG and calculated free testosterone when total values are borderline or binding protein may be abnormal, using the laboratory's validated method.
Key medicines
Transdermal testosterone gelApply the licensed daily starting amount to the specified clean dry skin and titrate from timed levels.
Long-acting testosterone undecanoate injectionAdminister the licensed deep intramuscular loading and maintenance schedule by trained staff with timed monitoring.