Testosterone Blood Test in Australia
Total, free, calculated free, and SHBG — what each measures, normal ranges for men and women, MBS criteria, and why morning timing and two readings matter so much.
The Short Answer
The testosterone blood test measures the main male sex hormone (which women have at lower levels too). In Australia, the typical adult male range is roughly 8 to 30 nmol/L for total testosterone, peaking in men aged 20 to 40 and declining gradually thereafter. A reliable diagnosis of low testosterone needs two morning samples (between 8 and 10 am) on separate days. Medicare covers the test under MBS item 66695 when there are clinical symptoms of androgen deficiency — not for fitness, “wellness,” or muscle gain.
Total vs Free vs Bioavailable vs SHBG
Testosterone in your blood does not all behave the same way. About 98% of total testosterone is bound to two carrier proteins — sex hormone-binding globulin (SHBG) and albumin — and is not directly available to your cells. Only the small unbound fraction (roughly 2%) is biologically active.
Total testosterone
Everything in the bloodstream — bound and free combined. The standard first-line test in Australia. Measured in nmol/L.
Free testosterone
The unbound, biologically active fraction. Measured directly (rare in Australia) or calculated from total testosterone, SHBG and albumin using the Vermeulen formula.
Bioavailable testosterone
Free testosterone plus the loosely albumin-bound portion that cells can still access. Less commonly reported but useful in older men.
SHBG
The main carrier protein. High SHBG (ageing, hyperthyroidism, oestrogen, liver disease) lowers free testosterone. Low SHBG (obesity, insulin resistance, hypothyroidism) does the opposite.
Normal Testosterone Ranges in Australia
Australian endocrinology bodies (Endocrine Society of Australia, Healthy Male) recommend interpreting testosterone in the context of age, time of day, and symptoms — not just the printed range.
Adult men, age 18 to 40
Peak adult range. Most healthy men sit between 15 and 25 nmol/L. Levels under 8 nmol/L on two morning samples meet diagnostic criteria for hypogonadism.
Adult men, age 40 to 60
Gradual age-related decline of ~1 to 2% per year. Symptoms matter more than the absolute number — a 50-year-old at 12 nmol/L may feel fine.
Adult men, age over 60
Many older men sit at the lower end of the range without symptoms. Treatment thresholds are lower and reserved for clear clinical deficiency.
Adult women
Levels above 3 nmol/L warrant investigation for PCOS, ovarian or adrenal pathology, or exogenous androgens. Below 0.3 nmol/L is rarely clinically significant.
Free testosterone (men)
Calculated from total testosterone, SHBG, and albumin (Vermeulen formula). Useful when total is borderline or SHBG is abnormal.
SHBG (sex hormone-binding globulin)
High SHBG (caused by ageing, hyperthyroidism, oestrogen) lowers free testosterone even when total is normal. Low SHBG (obesity, type 2 diabetes) does the opposite.
What Causes Low Testosterone in Men
Australian guidelines split low testosterone into four main groups. Identifying and treating the underlying cause is usually more important than simply replacing the hormone.
Primary (testicular)
Klinefelter syndrome, mumps orchitis, testicular trauma, chemotherapy, undescended testes, testicular cancer or surgery
Secondary (pituitary/hypothalamus)
Pituitary tumour, head injury, opioid medication, anabolic steroid use, severe weight loss, eating disorders
Functional/lifestyle
Obesity, type 2 diabetes, metabolic syndrome, sleep apnoea, chronic stress, excess alcohol, chronic illness
Medication-related
Long-term opioids, glucocorticoids, ketoconazole, anti-androgens, finasteride (mild)
High Testosterone in Women
For women, the clinically important question is usually whether testosterone is too high, not too low. Symptoms include unwanted facial or body hair (hirsutism), persistent acne, irregular or absent periods, scalp hair thinning, and difficulty conceiving.
PCOS
Most common cause — testosterone usually 2 to 5 nmol/L with irregular periods, hirsutism, acne, weight changes
Adrenal
Late-onset congenital adrenal hyperplasia, adrenal tumours (rare but serious if testosterone over 5 nmol/L)
Ovarian tumours
Rare androgen-secreting tumours — suspect with rapid-onset virilisation and very high levels
Exogenous
Anabolic steroid use, accidental exposure to a partner's testosterone gel
Cost — MBS, Medicare and Private Pay
MBS item 66695 — testosterone (and related sex hormones)
Bulk-billed by Sonic, Healius and Australian Clinical Labs collection centres when ordered by a GP for a specific clinical indication: symptoms of androgen deficiency, infertility investigation, suspected PCOS, hirsutism, suspected pituitary disease, or monitoring of established hormone replacement therapy. SHBG (item 66749) is usually rebated alongside.
Self-requested wellness or fitness testing
Not Medicare-rebated. Direct-to-consumer pathology services (i-screen, MyHealth Lab, OneStop Pathology, Vively, InstantScripts) charge $40 to $90 for total testosterone alone, or $120 to $250 for a hormone panel including SHBG, free testosterone, oestradiol, FSH, LH, and prolactin.
How to Prepare for the Test
Testosterone is one of the most timing-sensitive blood tests in medicine. Getting these conditions right is the difference between a useful result and a misleading one.
Morning only (8 to 10 am)
Testosterone peaks in the morning and falls 20 to 30% by mid-afternoon. Diagnostic guidelines specify 8 to 10 am samples for adult men.
Two separate samples
Day-to-day variation can be 20% or more. A diagnosis of low testosterone needs two morning samples, ideally at least a week apart, both showing low results.
Fasting preferred (not strict)
Fasting is not strictly required, but most labs recommend it because food can transiently lower testosterone. If your test is bundled with a lipid or glucose panel, you will be fasting anyway.
Avoid testing during acute illness
Cold, flu, surgery, hospital admission, or major stress can suppress testosterone for weeks. Wait at least 4 to 6 weeks after acute illness for a meaningful baseline.
Tell your GP about all medications
Opioids, glucocorticoids, anabolic steroids (current or past), and certain antifungals all affect testosterone. So can over-the-counter SARMs and prohormones bought online.
Avoid biotin supplements
High-dose biotin (often in hair/skin/nail supplements) can interfere with the immunoassay used to measure testosterone, giving falsely high or low results. Stop for 48 hours before testing.
Common Pitfalls and Misleading Results
A single low afternoon reading is meaningless
If your only testosterone test was taken at 2 pm and came back at 9 nmol/L, that does not mean you have low testosterone. Repeat the test between 8 and 10 am on two different mornings before any conclusion.
Total testosterone misses SHBG-driven cases
Older men, men with hyperthyroidism, and men taking oestrogenic medications often have high SHBG. Their total testosterone looks normal but free testosterone (the active fraction) is low. If symptoms are real and total is borderline, ask for SHBG and calculated free testosterone.
Anabolic steroid use suppresses for years
Even short cycles of anabolic-androgenic steroids can suppress your natural testosterone for 6 to 24 months after stopping. If you have ever used these (including SARMs, prohormones, or unprescribed testosterone gels or injections), tell your GP — it changes the interpretation completely.
Gender-affirming hormone therapy
Trans and gender-diverse Australians on testosterone therapy will see results in or above the typical male range as the goal of treatment. Reference ranges from this page do not apply — interpretation is done in consultation with your gender-affirming care provider, usually targeting mid-male levels (~15 to 20 nmol/L).
Frequently Asked Questions
What is a normal testosterone level for men in Australia?
Most Australian labs use a total testosterone reference range of approximately 8 to 30 nmol/L for adult men, with the average around 15 to 20 nmol/L. The range is age-dependent: levels naturally decline by about 1 to 2% per year from age 40. Two morning readings (8 to 10 am) are needed for diagnosis because levels vary day-to-day.
Does Medicare cover the testosterone blood test?
Yes, but only when there is a clinical reason. MBS item 66695 covers testosterone testing when ordered by a GP for symptoms suggesting androgen deficiency such as low libido, erectile dysfunction, infertility, loss of muscle mass, or unexplained osteoporosis. Tests requested for general wellness or fitness reasons are typically not Medicare-rebated and cost $40 to $90 private.
Why do I need a morning testosterone test?
Testosterone has a strong circadian rhythm, peaking between 8 and 10 am and falling by 20 to 30% by mid-afternoon. To diagnose low testosterone, Australian endocrinology guidelines require two separate morning samples taken between 8 and 10 am. Afternoon samples can falsely suggest deficiency.
What is the difference between total, free, and bioavailable testosterone?
Total testosterone is everything in the bloodstream. Most of it is bound to sex hormone-binding globulin (SHBG) and is biologically inactive. Free testosterone is the small fraction (about 2%) that is unbound and active. Bioavailable testosterone is free plus the loosely bound portion that cells can still use. If total testosterone is borderline, free or calculated free testosterone clarifies the picture.
Can women get tested for testosterone?
Yes. Women have testosterone too, at much lower levels (typically 0.5 to 2.5 nmol/L). Testing is usually done to investigate hirsutism (excess facial or body hair), acne, irregular periods, suspected polycystic ovary syndrome (PCOS), or unexplained virilisation. High testosterone in women is far more clinically significant than low.
What causes low testosterone in men?
Causes include ageing (gradual decline from age 40), obesity (fat tissue converts testosterone to oestrogen), type 2 diabetes, sleep apnoea, opioid use, anabolic steroid use (which causes long-term suppression after stopping), pituitary problems, testicular damage, chronic illness, and some medications. Identifying and treating the underlying cause matters more than just replacing the hormone.
Should I get my testosterone checked for fitness or muscle building?
Australian endocrinology guidelines do not support testing testosterone in healthy men without symptoms of androgen deficiency. There is no evidence that testosterone replacement helps muscle gain, fat loss, or athletic performance in men with normal levels, and it carries real risks including infertility, polycythaemia, and cardiovascular concerns. If you have genuine symptoms, see your GP for a proper workup.
Related Reading
Make Sense of Your Hormone Results
Upload your testosterone, SHBG, and full hormone panel results and SmarterBlood will explain each marker in plain English, calculate free testosterone if SHBG is provided, and track changes over time — using Australian reference ranges.
This page provides general educational information about the testosterone blood test in Australia. Hormone interpretation is highly individualised and depends on age, sex, symptoms, medications, and other clinical factors. SmarterBlood does not provide medical advice. Always discuss your results with a GP or endocrinologist.