A Guide to Sex Hormone Biomarkers

Q: Do I need a GP referral to get a sex hormone blood test in Australia?

In Australia, most pathology tests require a referral from a medical practitioner (GP or specialist) to be covered under Medicare. Without a referral, you may be able to access hormone testing through private pathology services, but you will need to pay the full cost out of pocket. Your GP can advise which specific hormone tests are appropriate for your situation and ensure they are ordered with the correct timing and clinical context.

Q: What is the difference between total testosterone and free testosterone?

Total testosterone measures all testosterone in the blood — both bound to proteins (primarily SHBG and albumin) and unbound. Free testosterone refers to the small fraction (typically 1–3%) that is unbound and biologically active. Free testosterone can be measured directly or estimated using total testosterone and SHBG via the free androgen index (FAI). The FAI is commonly used in Australia to assess androgen status, particularly in women with suspected PCOS.

Q: Can stress affect my sex hormone results?

Yes. Chronic stress elevates cortisol, which can suppress the hypothalamic-pituitary-gonadal axis and reduce the production of LH, FSH, oestradiol, testosterone, and progesterone. In women, this can manifest as irregular or absent periods (hypothalamic amenorrhoea). In men, chronic stress may contribute to lower testosterone levels. Acute stress on the day of testing is unlikely to cause clinically significant changes, but chronic stress patterns can meaningfully alter hormone levels over time.

Q: At what age should I start monitoring my sex hormones?

There is no universal recommendation, but testing becomes more relevant when specific concerns arise — such as menstrual irregularities, fertility assessment, or symptoms of hormonal imbalance. Proactively, including sex hormones in an annual health panel from your late 20s or early 30s establishes a personal baseline. For men, testosterone naturally declines from early adulthood at approximately 1% per year, so an early baseline provides valuable reference data. For women, tracking hormones becomes especially useful during the perimenopausal transition, typically beginning in the mid-40s.

Q: Why do my hormone results need to be timed with my menstrual cycle?

Female sex hormones fluctuate dramatically across the menstrual cycle. Oestradiol may be 150 pmol/L in the follicular phase and over 1,000 pmol/L at ovulation. Progesterone is low in the follicular phase and peaks in the luteal phase. LH surges briefly at ovulation. Testing at a standardised point in the cycle — typically days 2–5 for baseline hormones and day 21 for progesterone — ensures your results are comparable to reference ranges and to your own previous results.

Q: What does a high LH-to-FSH ratio mean?

An elevated LH-to-FSH ratio (greater than 2:1 or 3:1) has historically been associated with PCOS, although current international guidelines no longer require it for diagnosis. When seen alongside clinical features such as irregular periods, acne, excess hair growth, and elevated androgens, it may support the diagnosis. However, the ratio can vary with cycle timing and is not diagnostic on its own. Your healthcare provider will interpret it in the context of your full clinical picture.

Q: Are sex hormone reference ranges the same for all Australian pathology labs?

No. Reference ranges can vary between laboratories depending on the assay platform, methodology (immunoassay versus mass spectrometry), and the reference population used to establish the range. This is why your pathology report always includes the specific reference range for that laboratory. For serial monitoring, it is best to use the same laboratory each time so that results are directly comparable. The RCPA provides general reference intervals, but your laboratory's ranges take precedence.

Listen Health

Sex hormones are chemical messengers that regulate reproductive function, bone health, mood, metabolism, and much more. A sex hormone blood test measures circulating levels of key hormones — including oestrogen, testosterone, progesterone, SHBG, DHEA-S, LH, and FSH — to provide objective data about your hormonal status. These markers are relevant to fertility, menstrual health, menopause, androgen deficiency, and a range of conditions where hormonal imbalance may be a contributing factor. This guide explains what each sex hormone biomarker measures, why it matters, the reference ranges used in Australian pathology laboratories, and when testing may be appropriate. Whether you are tracking your health proactively or investigating specific symptoms, understanding these markers is a practical first step.

What are sex hormones and why do they matter?

Sex hormones are a group of steroid hormones produced primarily by the ovaries, testes, and adrenal glands. Despite the name, sex hormones do far more than regulate reproductive function. They influence bone density, cardiovascular health, body composition, mood, cognitive function, energy levels, and skin integrity across both sexes. The major sex hormones fall into three categories. Oestrogens — primarily oestradiol — are the dominant female sex hormones, though they are also produced in smaller amounts in males. Androgens — primarily testosterone — are the dominant male sex hormones, though they also play important roles in female physiology. Progestogens — primarily progesterone — are essential for the menstrual cycle and pregnancy. These hormones do not operate in isolation. They interact with each other and with regulatory hormones from the pituitary gland — luteinising hormone (LH) and follicle-stimulating hormone (FSH) — in tightly controlled feedback loops. When the system is functioning well, hormone levels rise and fall in predictable patterns. When something disrupts these patterns, the effects can be wide-ranging. Hormonal conditions are common in Australia. Polycystic ovary syndrome (PCOS) affects approximately 1 in 8 Australian women and is more prevalent in Aboriginal and Torres Strait Islander women (Jean Hailes, 2024). Androgen deficiency affects approximately 1 in 200 Australian men under 60, rising to approximately 1 in 20 men aged 70–79 (Healthy Male, 2023). Menopause — a natural hormonal transition — affects every woman, typically between the ages of 45 and 55. A sex hormone blood test provides measurable data about where your levels sit. It does not diagnose conditions on its own, but it gives you and your healthcare provider objective information to work with — particularly when symptoms are vague or overlap with other conditions. Tracking these biomarkers over time can reveal trends that a single snapshot would miss.

Oestrogen and oestradiol: the primary female sex hormone

Oestrogen is a group of hormones that includes oestradiol (E2), oestrone (E1), and oestriol (E3). Of these, oestradiol is the most biologically active and the form most commonly measured in blood tests. In premenopausal women, oestradiol is primarily produced by the ovaries and plays a central role in the menstrual cycle, bone metabolism, cardiovascular function, and brain health. In men, smaller amounts of oestradiol are produced by the testes and through conversion of testosterone in peripheral tissues. Oestradiol levels fluctuate significantly throughout the menstrual cycle. During the follicular phase (days 1–13), levels typically range from approximately 100–400 pmol/L. At the mid-cycle ovulatory peak, oestradiol can rise above 1,000 pmol/L before declining in the luteal phase. After menopause, oestradiol levels fall substantially — typically below 92 pmol/L (RCPA, 2024). In adult men, oestradiol levels are generally below 116 pmol/L. Your healthcare provider may request an oestradiol test when investigating irregular or absent menstrual periods, difficulty conceiving, menopausal symptoms such as hot flushes and sleep disturbance, bone density concerns, or as part of monitoring hormone therapy (Healthdirect, 2024). Because oestradiol fluctuates across the menstrual cycle, the timing of the blood draw matters. For baseline assessment, testing is typically performed in the early follicular phase (days 2–5 of the menstrual cycle), when oestradiol is at its lowest and most stable. It is worth noting that a single oestradiol result has limited diagnostic value in isolation. The Royal Australian College of General Practitioners (RACGP) notes that FSH and oestradiol have limited use in diagnosing menopausal symptoms due to day-to-day variability, particularly during the menopausal transition (RACGP, 2019). Oestradiol is most informative when interpreted alongside other hormones — particularly FSH, LH, and progesterone — and when tracked over multiple cycles or time points. Low oestradiol may be associated with menopause, primary ovarian insufficiency, hypothalamic amenorrhoea, or certain medications. Elevated oestradiol may be seen in ovarian hyperstimulation, some ovarian tumours, liver disease, or obesity (due to increased peripheral conversion of androgens to oestrogens). In all cases, results should be discussed with a qualified healthcare provider.

Testosterone: not just a male hormone

Testosterone is often thought of as exclusively a male hormone, but it is produced by both sexes and plays important physiological roles in everyone. In men, testosterone is the primary androgen, responsible for reproductive development, muscle mass, bone density, red blood cell production, libido, and mood. In women, testosterone — produced in smaller amounts by the ovaries and adrenal glands — contributes to bone health, muscle function, libido, and energy. Reference ranges for total testosterone differ substantially between the sexes. For adult men aged 21–35, the reference interval for total testosterone measured by mass spectrometry is approximately 10.4–30.1 nmol/L (Healthy Male, 2023). This range shifts with age: in men aged 70–89, the reference interval is approximately 6.4–25.7 nmol/L, reflecting the gradual age-related decline of approximately 1% per year from early adulthood (RACGP, 2014). For adult women of reproductive age, total testosterone typically falls below 2 nmol/L (Australian Prescriber, 2019). Levels above 2 nmol/L may warrant further investigation, while levels above 10 nmol/L raise concern for androgen-secreting tumours. Testing methodology matters. The RACGP and Endocrine Society of Australia recommend that serum total testosterone be measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS), which is more accurate than older immunoassay methods — particularly at the lower concentrations seen in women and older men (RACGP, 2014). Blood should be drawn in the morning after fasting, as testosterone follows a diurnal pattern with levels highest in the early morning. For a diagnosis of androgen deficiency in men, at least two measurements of serum testosterone — collected on separate days — are required, alongside clinical signs and symptoms (Healthy Male, 2023). The Pharmaceutical Benefits Scheme (PBS) criteria require a serum testosterone below 6 nmol/L, or between 6–15 nmol/L with LH at least 1.5 times the upper limit of the reference range (or above 14 IU/L), to qualify for testosterone replacement therapy. In women, elevated testosterone is a key feature of PCOS and is assessed using calculated free testosterone, free androgen index, or calculated bioavailable testosterone. Low testosterone in women is less well defined clinically, and there are currently no validated female testosterone deficiency thresholds endorsed by Australian guidelines. If you have concerns about your testosterone levels, discuss them with your GP or healthcare provider.

SHBG, DHEA-S, and progesterone: the supporting cast

While oestradiol and testosterone often take centre stage, three other biomarkers provide critical context for interpreting sex hormone status. Sex hormone-binding globulin (SHBG) is a protein produced by the liver that binds to testosterone and oestradiol in the bloodstream, rendering them biologically inactive. Only the unbound (free) fraction of these hormones is available for tissues to use. SHBG therefore acts as a regulator of hormone availability. Australian reference ranges for SHBG are approximately 17–78 nmol/L in males and 26–148 nmol/L in females (Royal Melbourne Hospital, 2024). Low SHBG is associated with obesity, insulin resistance, PCOS, type 2 diabetes, and hypothyroidism. High SHBG may be seen with liver disease, hyperthyroidism, ageing, oestrogen therapy, and eating disorders. SHBG is commonly ordered alongside testosterone to calculate the free androgen index (FAI), which provides a more accurate estimate of biologically active testosterone than total testosterone alone. Dehydroepiandrosterone sulphate (DHEA-S) is the most abundant circulating steroid hormone and serves as a precursor to both testosterone and oestrogen. It is produced almost entirely by the adrenal glands. DHEA-S levels peak in early adulthood and decline progressively with age. Australian reference ranges are approximately 2.0–13.9 µmol/L for women under 45 years, 0.8–7.7 µmol/L for women 45 years and over, and 1.3–16.1 µmol/L for men (Royal Melbourne Hospital, 2024). Elevated DHEA-S may indicate adrenal hyperplasia, adrenal tumours, or PCOS. Low DHEA-S may reflect adrenal insufficiency or the natural decline associated with ageing. DHEA-S is a useful marker for distinguishing adrenal from ovarian sources of androgen excess. Progesterone is a steroid hormone essential for the menstrual cycle and pregnancy. In premenopausal women, progesterone is produced by the corpus luteum after ovulation and rises significantly in the luteal phase. Follicular-phase progesterone levels are approximately 1.0–4.8 nmol/L, while mid-luteal phase levels rise to approximately 16–59 nmol/L. In men, progesterone is present at lower levels, typically 0.6–5.2 nmol/L. Progesterone testing is most commonly used to confirm ovulation — a mid-luteal progesterone above 20–25 nmol/L indicates that ovulation has occurred in that cycle (Australian Prescriber, 2019). The test should be timed approximately seven days before the expected next period (day 21 of a 28-day cycle, day 23 of a 30-day cycle). Low luteal-phase progesterone may reflect anovulation, luteal phase deficiency, or mistimed blood collection.

Track your sex hormone biomarkers

Understanding your hormonal health starts with data. A comprehensive sex hormone panel — including oestradiol, testosterone, SHBG, DHEA-S, progesterone, LH, and FSH — provides a detailed snapshot of your hormonal status. Track your results over time to establish your personal baseline and detect changes early.

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LH and FSH: the pituitary regulators

Luteinising hormone (LH) and follicle-stimulating hormone (FSH) are gonadotrophins — hormones produced by the pituitary gland that regulate the function of the ovaries and testes. Although they are not sex hormones themselves, they are inseparable from any meaningful sex hormone assessment because they control the production of oestrogen, testosterone, and progesterone. In women, FSH stimulates the growth and maturation of ovarian follicles in the first half of the menstrual cycle. LH triggers ovulation — the release of a mature egg — through a sharp mid-cycle surge. After ovulation, LH supports the corpus luteum, which produces progesterone. In men, FSH stimulates sperm production in the testes, while LH stimulates the Leydig cells to produce testosterone (Healthdirect, 2024). Australian reference ranges for reproductive-age adults are approximately 2–15 IU/L for LH and 1–8 IU/L for FSH in women (varying across the menstrual cycle), and 2–10 IU/L for LH and 1–5 IU/L for FSH in men (RCPA, 2024). In postmenopausal women, both LH and FSH rise substantially as the ovaries cease oestradiol production — FSH above 20–30 IU/L is consistent with ovarian failure or menopause (Australian Prescriber, 2019). The LH-to-FSH ratio is clinically relevant in certain conditions. In PCOS, a reversed or elevated LH:FSH ratio (greater than 2:1 or 3:1) has historically been considered a diagnostic feature, although current international guidelines no longer require this for diagnosis. Nonetheless, an elevated LH:FSH ratio in the context of other clinical features may support the diagnosis (RACGP, 2012). Low LH and FSH alongside low sex hormones (oestradiol or testosterone) suggest a problem at the pituitary or hypothalamic level — known as hypogonadotrophic hypogonadism. This may result from stress, excessive exercise, low body weight, pituitary tumours, or certain medications. High LH and FSH alongside low sex hormones indicate that the gonads are not responding to pituitary stimulation — known as hypergonadotrophic hypogonadism — and may reflect primary ovarian insufficiency, menopause, or testicular failure. As with other sex hormones, LH and FSH fluctuate across the menstrual cycle, so timing matters. For baseline assessment in women, testing is typically performed on days 2–5 of the menstrual cycle. In men, timing is less critical, though morning samples are preferred for consistency.

When to consider a sex hormone blood test

Sex hormone testing is not routinely included in standard blood panels, but there are several clinical scenarios where it provides valuable data. Menstrual irregularities are one of the most common reasons for hormone testing. If periods are absent, irregular, unusually heavy, or unusually light, measuring oestradiol, LH, FSH, testosterone, and SHBG can help clarify the underlying pattern — whether that is PCOS, hypothalamic amenorrhoea, premature ovarian insufficiency, or thyroid-related disruption. Fertility assessment often includes a hormone panel. For women, day 2–5 FSH and oestradiol provide information about ovarian reserve, while mid-luteal progesterone confirms ovulation. For men, testosterone, LH, and FSH are measured alongside semen analysis to assess testicular function and sperm production (Australian Prescriber, 2019). Menopausal symptoms may prompt testing, although the RACGP notes that menopause is primarily a clinical diagnosis in women over 45 with characteristic symptoms. Hormone testing is more useful in women under 45 where premature menopause is suspected, or when symptoms are atypical and other diagnoses need to be excluded (RACGP, 2019). Suspected androgen excess in women — presenting as acne, excess facial or body hair, scalp hair thinning, or irregular periods — warrants measurement of total testosterone, SHBG, free androgen index, and DHEA-S to assess the degree and source of androgen elevation. Suspected androgen deficiency in men — presenting as reduced libido, erectile dysfunction, fatigue, reduced muscle mass, depressed mood, or decreased bone density — requires at least two fasting morning testosterone measurements on separate days, along with LH and FSH (Healthy Male, 2023). Proactive health tracking is another valid reason for including sex hormones in a comprehensive blood panel. Tracking these biomarkers annually provides a personal baseline, making it easier to detect gradual changes — such as declining testosterone in men or the hormonal shifts of perimenopause in women — before they become symptomatic. Timing and preparation can affect the accuracy of sex hormone results. In women, baseline testing is best performed on days 2–5 of the menstrual cycle. Testosterone should be measured in the morning after fasting. SHBG and DHEA-S are less time-sensitive but are most consistent when drawn fasting in the morning. Your pathology report will include laboratory-specific reference ranges — always use these as the primary point of comparison for your results.

How to interpret your results and what to do next

Sex hormone results are most meaningful when interpreted as a panel rather than individual numbers. A single biomarker rarely tells the whole story. For example, a total testosterone result in isolation is difficult to interpret without knowing SHBG levels (which determine how much testosterone is biologically active) and LH and FSH levels (which reveal whether the pituitary is driving production up or down). Reference ranges represent the statistical range covering approximately 95% of a healthy population. Being within the reference range does not automatically mean the level is optimal for you, and being slightly outside the range does not necessarily indicate disease. Context matters — your age, sex, menstrual cycle phase, medication use, time of blood draw, and clinical symptoms all influence interpretation. Some important principles for interpretation. Trends are more informative than snapshots. A testosterone of 12 nmol/L in a 45-year-old man is within range, but if it was 22 nmol/L two years ago, the downward trend is clinically relevant. Cycle timing affects female hormones significantly — a progesterone of 5 nmol/L on day 21 suggests anovulation, but the same level on day 7 is entirely normal. Laboratory methodology matters — testosterone results from immunoassay and mass spectrometry are not directly comparable, so aim to use the same laboratory for serial testing. It is also important to distinguish between reference ranges and what some practitioners describe as "optimal" ranges. Reference ranges are statistically derived from healthy populations and are the standard used in Australian pathology. Some integrative or functional medicine practitioners use narrower ranges that they consider optimal, but these are not endorsed by the RCPA or RACGP. If your results are within the laboratory reference range but you are experiencing symptoms, discuss this with your healthcare provider rather than self-interpreting. Blood testing provides data — it does not provide treatment or diagnoses. Your results should always be discussed with a qualified healthcare provider who can interpret them in the context of your full clinical picture. If a hormonal condition is identified, your GP may refer you to an endocrinologist or reproductive specialist for further assessment and management. Tracking your sex hormone biomarkers over time — ideally annually as part of a comprehensive health panel — gives you and your healthcare provider the most useful longitudinal data. Gradual hormonal shifts, seasonal variations, and the effects of lifestyle changes become visible over multiple data points in a way that a single test cannot capture.

Key Takeaways

A sex hormone blood test typically measures oestradiol, testosterone, SHBG, DHEA-S, progesterone, LH, and FSH — each providing different information about hormonal health.
Sex hormones affect far more than reproduction, influencing bone density, cardiovascular health, mood, energy, and body composition in both sexes.
Australian reference ranges use SI units (nmol/L, pmol/L, µmol/L, IU/L) — always check the specific ranges on your pathology report as they vary between laboratories.
Timing matters: baseline female hormone testing is best on days 2–5 of the menstrual cycle, and testosterone should be measured in the morning after fasting.
PCOS affects approximately 1 in 8 Australian women, and androgen deficiency affects approximately 1 in 200 men under 60 — both are diagnosed through sex hormone blood tests.
SHBG is essential for interpreting testosterone results because it determines how much testosterone is biologically active.
Trends over time are more informative than single results — annual tracking establishes a personal baseline that helps detect gradual hormonal changes early.
Blood tests provide data, not diagnoses. Always discuss your results with a qualified healthcare provider.

Frequently Asked Questions

AHPRA Disclaimer: This information is general in nature and should not replace individual medical advice. Always discuss your test results and health concerns with a registered healthcare practitioner.

A Guide to Sex Hormone Biomarkers

What are sex hormones and why do they matter?

Oestrogen and oestradiol: the primary female sex hormone

Testosterone: not just a male hormone

SHBG, DHEA-S, and progesterone: the supporting cast

Track your sex hormone biomarkers

LH and FSH: the pituitary regulators

When to consider a sex hormone blood test

How to interpret your results and what to do next

Key Takeaways

Frequently Asked Questions

References

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