Testosterone, Total Test
The total testosterone test measures the sum of free, albumin-bound, and SHBG-bound testosterone in serum. It is the first-line androgen assessment in males with suspected hypogonadism and in females with hyperandrogenism, requiring morning collection to account for diurnal variation and interpretation alongside SHBG, LH, and FSH to classify androgen disorders.
1
Biomarkers
Blood (serum)
Sample
3–5 business days
Turnaround
No
Fasting
What is the Total Testosterone test?
The Testosterone, Total Test measures the sum of free, albumin-bound, and SHBG-bound testosterone in serum. It is the initial androgen assessment in males with suspected hypogonadism — symptoms such as fatigue, reduced libido, erectile dysfunction, loss of muscle mass, or mood disturbance — and in females with clinical or biochemical evidence of androgen excess, including hirsutism, menstrual irregularity, or virilisation. Practitioners order total testosterone to screen, confirm, and classify androgen disorders. In men the first step is a morning sample; a low result prompts a repeat confirmation alongside LH, FSH, and often prolactin to distinguish testicular failure from hypothalamic–pituitary suppression. In women an elevated total testosterone is the entry point into a differential that spans polycystic ovary syndrome, adrenal hyperplasia, and tumour. Because total testosterone includes protein-bound hormone, it must be interpreted in light of SHBG status, which is altered by obesity, liver disease, thyroid dysfunction, and exogenous oestrogen or androgen.
What does the Total Testosterone test measure?
Testosterone is the principal androgen synthesised in testicular Leydig cells under luteinising hormone control, with smaller contributions from the adrenal cortex. In the circulation roughly 98 per cent is protein-bound — about 40 per cent to sex hormone-binding globulin (SHBG) with high affinity and 58 per cent to albumin with lower affinity — leaving only 1–2 per cent as free, bioavailable hormone. Total testosterone reflects all three fractions. Secretion is pulsatile and follows a circadian rhythm with peak values in the early morning and a nadir in the evening; the amplitude of this rhythm diminishes with age and chronic illness.
Total testosterone is the cornerstone of hypogonadism diagnosis in males and the first-line androgen marker in females with suspected hyperandrogenism. In men a low morning total testosterone triggers further investigation — repeat confirmatory testing, measurement of LH and FSH to classify primary versus secondary hypogonadism, and consideration of free or bioavailable testosterone when SHBG is abnormal. In women elevated total testosterone suggests polycystic ovary syndrome, non-classic congenital adrenal hyperplasia, or androgen-secreting neoplasms. Because total testosterone includes protein-bound fractions, alterations in SHBG — due to obesity, ageing, thyroid disease, or oestrogen — can shift the total value without changing free hormone, so clinical context and ancillary tests are essential to interpretation.
Why is the Total Testosterone test ordered?
- Evaluation of suspected male hypogonadism in patients with fatigue, reduced libido, erectile dysfunction, loss of lean mass, or depression
- Investigation of delayed puberty in adolescent males or precocious puberty in children of either sex
- Assessment of hyperandrogenism in females presenting with hirsutism, acne, menstrual irregularity, or clinical virilisation
- Monitoring of testosterone replacement therapy in hypogonadal men, drawn as a trough (before the next dose) or mid-interval depending on formulation
- Work-up of infertility in males, interpreted with semen analysis, LH, FSH, and prolactin
- Screening for androgen-secreting neoplasms when total testosterone is markedly elevated in a female patient
- Diagnosis of primary versus secondary hypogonadism when combined with gonadotropins, or of polycystic ovary syndrome when integrated with clinical and ultrasound findings
- Assessment of transgender patients on gender-affirming hormone therapy, to guide dose titration and confirm target androgen levels
Sample collection and turnaround
Sample type
Blood (serum)
Fasting required
No
Collection method
Venipuncture at patient service centre
Turnaround
3–5 business days
Collection notes
Draw in the morning, ideally before 10:00, to account for diurnal variation when assessing hypogonadism. Document testosterone or anabolic steroid use, opioids, glucocorticoids, and high-dose biotin. Defer testing during acute illness where possible, and confirm a low result on a separate morning sample.
Specimen requirements
Minimum 0.5 mL serum (gel separator acceptable). Separate from cells and refrigerate or freeze if not analysed within a few hours. Note the performing laboratory and assay method for serial comparability.
What can affect Total Testosterone results?
Testosterone exhibits diurnal variation with a morning peak and evening nadir; samples drawn late in the day can underestimate true levels by 20–30 per cent, so hypogonadism assessment requires early-morning collection.
Acute stress and systemic illness suppress the hypothalamic–pituitary–gonadal axis, transiently lowering testosterone; defer elective testing until recovery to avoid false-positive hypogonadism diagnoses.
Adiposity lowers SHBG and increases aromatisation of androgens to oestrogens, reducing total testosterone; free or bioavailable testosterone may be disproportionately preserved.
Testosterone replacement or anabolic-steroid use raises total testosterone; the result reflects both endogenous and exogenous hormone, and suppresses endogenous production via negative feedback.
Chronic glucocorticoid and opioid use suppress gonadotropin secretion, lowering testosterone; document medications when interpreting a low result.
Biotin interferes with some immunoassays used for testosterone and hormone panels; discontinue supplements for at least 72 hours before the draw or confirm the laboratory uses a method unaffected by biotin.
What do Total Testosterone results mean?
Elevated
In males, elevated total testosterone is rare outside the context of exogenous androgen use or testosterone therapy. In females, elevation suggests polycystic ovary syndrome (mild–moderate increase), non-classic congenital adrenal hyperplasia (moderate), or an androgen-secreting ovarian or adrenal tumour (marked, often >200 ng/dL). Further work-up includes DHEA-S, 17-hydroxyprogesterone, and imaging as indicated.
Normal
A normal morning total testosterone in a symptomatic male does not exclude androgen deficiency if SHBG is elevated (obesity, ageing, hypothyroidism), masking a low free fraction; measure free or bioavailable testosterone or calculate the free androgen index in this setting. In females, normal total testosterone with clinical hyperandrogenism warrants measurement of free testosterone or androgen metabolites.
Reduced
In males, a morning total testosterone below 300 ng/dL on two occasions supports hypogonadism when symptoms are present; classify as primary (high LH/FSH) or secondary (low/normal gonadotropins). Causes include Klinefelter syndrome, testicular injury, pituitary or hypothalamic disease, obesity, metabolic syndrome, opioid or glucocorticoid therapy, and ageing. In females, low testosterone is not clinically significant in most cases but may reflect hypopituitarism or adrenal insufficiency when other hormone axes are affected.
Note: Total testosterone must be drawn in the morning to account for diurnal variation, and a single low value requires confirmation on a separate occasion before diagnosing hypogonadism. SHBG alterations — due to obesity, liver disease, thyroid dysfunction, or medications — shift total testosterone without necessarily changing free hormone, so interpret total testosterone alongside clinical context, SHBG, and free or bioavailable testosterone when discordance is suspected. Immunoassays are less specific than liquid chromatography–tandem mass spectrometry, particularly at low concentrations and in females; method matters for serial monitoring.
Frequently asked questions
Testosterone secretion follows a circadian rhythm with peak levels in the early morning and a nadir in the evening. Samples drawn late in the day can underestimate true levels by 20–30 per cent, so hypogonadism assessment requires collection before 10:00.
How to access the Total Testosterone test
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Published: October 7, 2026
Last reviewed: October 7, 2026
- Bhasin S, et al. Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. (2018)
- Legro RS, et al. Diagnosis and treatment of polycystic ovary syndrome: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. (2013)
- Rosner W, et al. Position statement: utility, limitations, and pitfalls in measuring testosterone: an Endocrine Society position statement. J Clin Endocrinol Metab. (2007)
- Rothman MS, et al. Reexamination of testosterone, dihydrotestosterone, estradiol and estrone levels across the menstrual cycle and in postmenopausal women measured by liquid chromatography–tandem mass spectrometry. Steroids. (2011)
This content is for licensed healthcare practitioners only and does not constitute medical advice. Clinical decisions should be based on the full clinical picture and not on any single test result.
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