I'm going to be upfront: I'm a man writing about a condition that overwhelmingly affects women. I don't have PCOS. I can't fully understand what it feels like to live with it.

But my girlfriend does. And watching her navigate the diagnosis gave me a perspective I wouldn't have had otherwise. The years of confusing symptoms. The GP visits that went nowhere. The ultrasound that finally triggered the conversation. The fear about fertility that hit before anyone had mentioned treatment.

She was diagnosed in her mid-twenties. Looking back, the signs had been there since her teens: irregular periods, persistent acne long past puberty, gradual weight gain that didn't respond to the things weight gain is supposed to respond to. Nobody connected the dots until she was 24 and a GP finally ordered hormone bloods alongside a pelvic ultrasound.

The thing that surprised me most was how much bigger it was than I expected. It's not just a period problem. It's not just a fertility issue. It's a metabolic, hormonal, and often psychological condition that touches nearly every system in the body. It affects roughly one in eight Australian women.

Australia, incidentally, led the world on this. The 2023 International PCOS Guideline was developed by Monash University under Professor Helena Teede, with input from over 100 experts across 71 countries. That matters because it means the clinical framework for PCOS assessment and management in this country is among the best in the world.

This article covers the blood tests used to assess PCOS, what each one measures, and why the metabolic dimension of PCOS deserves far more attention than it usually gets. I wrote it partly because our competitor analysis showed zero PCOS-specific content from other Australian testing companies (astonishing for a condition this common) and partly because my girlfriend read the first draft and said "if I'd had this article when I was 21, I would've pushed for testing three years earlier."

A note before we get into it

What PCOS actually is, and what it isn't

The name "polycystic ovary syndrome" is, by common agreement, terrible. It implies the problem is cysts on the ovaries. It's not. The "cysts" are actually small, immature follicles. They're a feature of the condition, not the cause. Many women with PCOS don't have polycystic ovaries on ultrasound at all.

PCOS is fundamentally a hormonal and metabolic condition. At its core, it involves elevated androgens (male-type hormones like testosterone), which interact with insulin resistance to produce a cascade of symptoms that vary enormously from person to person.

Common features include irregular or absent periods, excess facial or body hair (hirsutism), acne along the jawline and chin, hair thinning on the scalp, difficulty managing weight, and reduced fertility. But not everyone has every symptom. Some women have mainly androgenic symptoms. Some have mainly metabolic features. Some have irregular cycles with no visible signs of androgen excess. That variability is part of what makes PCOS so challenging to diagnose, and so easy to miss.

An estimated 85% of women with PCOS have some degree of insulin resistance. That means PCOS is not just a reproductive disorder. It carries genuine metabolic implications including increased risk of type 2 diabetes, cardiovascular disease, and metabolic syndrome. The metabolic dimension is, in my observation, the part that's most consistently underappreciated.

How PCOS is diagnosed

The 2023 International PCOS Guideline, led by Monash University, refined the diagnostic approach. Diagnosis is based on the Rotterdam criteria, which require two of the following three features:

1. Irregular menstrual cycles (oligo-ovulation or anovulation)

In adults: cycles consistently shorter than 21 days or longer than 35 days, or fewer than 8 cycles per year, or absence of periods for 90+ days. In adolescents: irregular cycles more than 2 years after menarche.

2. Clinical or biochemical hyperandrogenism

Clinical signs include hirsutism (excess hair growth in androgen-sensitive areas), persistent acne, or androgenic alopecia (scalp hair thinning). Biochemical signs include elevated total testosterone, free testosterone, or free androgen index on blood testing.

3. Polycystic ovarian morphology on ultrasound

In adults: 20 or more follicles per ovary and/or ovarian volume greater than 10 mL. Ultrasound is not recommended for diagnosis in adolescents within 8 years of menarche, as polycystic morphology overlaps with normal ovarian development.

A key update from the 2023 guideline: When hyperandrogenism and ovulatory dysfunction are both present, ultrasound is no longer necessary for diagnosis. That's a meaningful shift. Many women can now be diagnosed through clinical assessment and blood tests alone, without needing imaging.

Other conditions that mimic PCOS need to be excluded as part of the diagnostic workup. These include thyroid dysfunction, congenital adrenal hyperplasia, hyperprolactinaemia, and Cushing's syndrome.

The blood tests used in PCOS assessment

Here's what typically gets ordered and why.

The metabolic side of PCOS most people don't hear about

This is the section I think matters most, and it's the part my girlfriend says she was never properly told about.

PCOS is commonly framed as a reproductive condition. The conversation centres on periods, fertility, and hormones. Those things are important. Fertility concerns are the most distressing aspect of diagnosis for many women, according to Australian research.

But the metabolic dimension is where the long-term health implications live.

Women with PCOS are approximately 4 times more likely to develop type 2 diabetes than women without PCOS. They have a higher risk of cardiovascular disease, metabolic syndrome, and gestational diabetes. Approximately 85% have some degree of insulin resistance. Their bodies need to produce more insulin to maintain blood sugar control, and that excess insulin drives many of the condition's hormonal features.

The relationship is bidirectional: insulin resistance worsens androgen excess, and androgen excess may worsen insulin resistance. It's a feedback loop. That's why weight management in PCOS is genuinely harder. Not because of a lack of willpower, but because the metabolic environment is actively working against it.

I'll be honest, this frustrated me when I learned about it. My girlfriend had spent years feeling guilty about not being able to lose weight the way other people seemed to. Nobody had explained the insulin piece. Nobody had framed PCOS as a metabolic condition that makes weight regulation fundamentally different. The diagnosis itself was almost a relief. Not because it was good news, but because it finally explained a pattern she'd been fighting without understanding.

Metabolic screening matters. HbA1c, fasting glucose, fasting insulin, and lipids aren't optional extras in PCOS. They're part of understanding the condition and managing it over time.

Who should be testing

Women with irregular periods and one or more signs of androgen excess (acne, hirsutism, hair thinning). This is the classic PCOS picture. Blood tests are a key part of the diagnostic workup.

Adolescents with persistent menstrual irregularity more than 2 years after first period, especially if accompanied by acne or excess hair growth. Diagnosis in adolescents requires care (many PCOS features overlap with normal puberty), but "at-risk" identification and monitoring is recommended by the 2023 guideline.

Women diagnosed with PCOS who haven't had metabolic screening. If your diagnosis was based on ultrasound and symptoms without blood work, the metabolic side may have been missed.

Women with PCOS planning pregnancy. Pre-conception metabolic screening (HbA1c, fasting glucose, lipids) is recommended to identify and address metabolic risk factors before pregnancy.

Women with a family history of PCOS or type 2 diabetes. PCOS has a strong genetic component. Up to a third of women with PCOS have a female relative with the condition.

Women experiencing unexplained weight gain and insulin resistance patterns. Even without classic PCOS symptoms, the metabolic and hormonal panel can reveal patterns worth investigating.

Understanding your results

PCOS blood results need to be interpreted as a pattern, not individual numbers. Here's a general guide.

Testosterone:

Total testosterone in women is typically below 2.6 nmol/L. Levels above this may suggest androgen excess. Free testosterone or Free Androgen Index (FAI) may be elevated even when total testosterone is normal. Check both if PCOS is suspected.

SHBG:

Low SHBG (below 30 nmol/L in particular) is common in PCOS and reflects insulin resistance. Low SHBG amplifies the effect of circulating testosterone.

LH and FSH:

Elevated LH relative to FSH is common in PCOS but not diagnostic on its own. Timing matters: LH and FSH should ideally be measured in the early follicular phase (days 2–5 of the menstrual cycle) if possible.

HbA1c:

Below 42 mmol/mol (6.0%) is normal. 42–47 mmol/mol (6.0–6.4%) suggests pre-diabetes. 48 mmol/mol (6.5%) or above suggests diabetes. Women with PCOS should be aware that their risk of progression is higher than the general population.

Fasting Glucose:

Below 5.5 mmol/L is generally normal. 5.5–6.9 mmol/L suggests impaired fasting glucose. 7.0 mmol/L or above suggests diabetes.

Lipids:

The typical PCOS lipid pattern: elevated triglycerides, elevated LDL, reduced HDL. This pattern reflects insulin resistance and increases cardiovascular risk.

TSH:

Should be within normal range (approximately 0.4–4.0 mU/L). If abnormal, thyroid dysfunction should be investigated separately. See our thyroid function test guide for more detail.

The emotional weight of a PCOS diagnosis

I debated whether to include this section. It's not about blood tests, and I'm not the right person to speak to the emotional experience of a PCOS diagnosis. But I've watched someone I love go through it, and I think leaving it out would be dishonest.

Australian research found that approximately 65% of young women were unhappy or worried about their initial PCOS diagnosis, with 72% reporting that fertility concerns were the most distressing aspect. Internationally, studies suggest the average time to diagnosis is around 2.5 years, with nearly half of women visiting three or more healthcare providers before getting a diagnosis.

The 2023 guideline explicitly acknowledges this: "Individuals affected report limited knowledge and dismissive attitudes from health professionals." That's the guideline talking, not me.

My girlfriend's experience tracked with this. She felt dismissed for years. When the diagnosis finally came, it was validating and frightening at the same time. There's a name for this, there's a reason. Fertility was the first thing she Googled. Diabetes risk was the second.

I include this because I think anyone reading this article should know: if you're feeling dismissed, if your concerns aren't being investigated, if you've been told it's "just stress" or "just your weight" — you're not alone in that experience, and you're not wrong to push for answers. Blood tests are one way to push.

Tests to consider through Bloody Good

Hormone assessment for PCOS:

Testosterone Blood Test (total testosterone)

Testosterone Free/Total + SHBG (total testosterone, free testosterone, SHBG, and Free Androgen Index). This is the more complete option if you're investigating possible PCOS.

FSH Blood Test (follicle-stimulating hormone)

LH Blood Test (luteinising hormone)

DHEAS Blood Test (adrenal androgen)

Metabolic screening for PCOS:

HbA1c (3-month blood sugar average)

Fasting Glucose (blood sugar snapshot)

Fasting Insulin (insulin level, useful for detecting hyperinsulinaemia)

Cholesterol (Lipid Studies inc. HDL) (full lipid panel)

Rule-out tests:

Thyroid Function Test (TFT) (excludes thyroid dysfunction)

Prolactin Blood Test (excludes hyperprolactinaemia)

Related tests for a complete picture:

Iron Studies (Including Ferritin) (heavy periods in PCOS can cause iron depletion)

Vitamin D (25-OH) (commonly low in PCOS and may influence insulin resistance)

If you want a broad baseline:

The Bloody Good Test covers 100 biomarkers including many of the markers above. For women who want a broad baseline alongside PCOS-specific testing, it provides wide coverage in a single blood draw.

What to do after testing

If blood work supports a PCOS diagnosis: Take the results to your GP or specialist. Blood tests are one component. The diagnosis also requires clinical assessment (symptoms, medical history, physical examination, and potentially ultrasound).

Address the metabolic dimension early. If HbA1c, glucose, insulin, or lipids are abnormal, these need attention, not just the hormonal symptoms. Lifestyle interventions (nutrition, physical activity, sleep, stress management) are first-line for metabolic management in PCOS. The evidence for Mediterranean-style dietary patterns is the strongest.

Don't let fertility fear drive every decision. PCOS is the leading cause of anovulatory infertility, but many women with PCOS can conceive, often with support. The 2023 guideline now recommends letrozole as first-line for ovulation induction, ahead of clomiphene citrate. If fertility is a concern, a conversation with a reproductive specialist is more useful than catastrophising from search results.

Monitor over time. PCOS is a lifelong condition. Regular metabolic screening (HbA1c, lipids, blood pressure) is recommended throughout life, not just at diagnosis. How often depends on your baseline results and risk factors, but annual metabolic checks are a reasonable starting point.

Seek support. PCOS has a well-documented association with anxiety and depression. The 2023 guideline recommends routine psychological screening. If your mental health is affected, that matters as much as your blood results — and deserves the same level of attention.

Explore more biomarkers

If you want to go deeper into any of the markers covered here, the Bloody Good biomarker directory has detailed pages on what each test measures and how to think about results.

Browse the Bloody Good Biomarker Directory