Polycystic Ovary Syndrome (PCOS) affects 8–13% of reproductive-aged women and is often under diagnosed. The 2023 International Evidence-Based Guideline for the Assessment and Management of PCOS provides updated recommendations for diagnosis and treatment, replacing previous versions. This article summarises the key PCOS blood tests recommended for diagnosis, based on the 2023 guidelines, and how to access them in Australia. They can also be used to see improvements by lifestyle interventions.
This list should serve as a point for discussion with your GP or professional health team. It is important to know where you are currently at and what is the normal range for healthy women.
1. Reproductive Hormone PCOS Blood Tests
When to test: Tests are done after 3 months of being off hormonal birth control. If your periods come regularly, hormone tests should be done early in your cycle (days 2–5). If your periods are irregular or missing, the timing is more flexible.
- Anti-Müllerian Hormone (AMH): This test looks at how many small egg follicles are in your ovaries. High levels are common in PCOS and can be used instead of an ultrasound to help with diagnosis.
- Androgens (like testosterone and DHEAS): These are “male-type” hormones. High levels can lead to acne, unwanted hair growth, and irregular periods. Free testosterone is considered the most helpful for diagnosis.
- Sex Hormone-Binding Globulin (SHBG): This protein binds to testosterone in the blood. If SHBG is low, there’s more active testosterone, which can make symptoms worse. It’s also used to calculate the Free Androgen Index (FAI).
- Prolactin: This hormone is checked to make sure high levels aren’t causing missed periods or milk production from the breasts. If it’s high, something other than PCOS could be the cause.
- FSH, LH, and Oestradiol: These hormones are still checked but are not used on their own to diagnose PCOS. The LH/FSH ratio is no longer seen as reliable.
2. Thyroid Function PCOS Blood Tests
Why it’s important: An underactive thyroid can cause symptoms that are a lot like PCOS—like tiredness, weight gain, and irregular periods.
- TSH (Thyroid-Stimulating Hormone): This is the main test to check if your thyroid is working properly.
- Free T4 and thyroid antibodies: These may be done if TSH is abnormal, to give more details about thyroid function or autoimmune thyroid disease.
3. Metabolic and Insulin Resistance Assessment
Why it matters: Many people with PCOS have trouble using insulin properly. This can lead to higher risks of diabetes and heart disease, so it’s important to test how your body handles sugar and fat.
- Oral Glucose Tolerance Test (OGTT): You drink a sugary liquid and have blood tests over two hours. This checks how well your body handles sugar and is the best test to spot early signs of diabetes.
- HbA1c: Shows your average blood sugar over the past few months. It’s a helpful test, but OGTT is preferred if PCOS is suspected.
- Fasting insulin and glucose (used to calculate HOMA-IR): These test your insulin resistance, although HOMA-IR is not always used in regular practice.
- Lipid Profile: This test checks your cholesterol and other fats in your blood. High levels of LDL (bad cholesterol) or triglycerides and low levels of HDL (good cholesterol) can raise your risk of heart disease.
Accessing Tests in Australia
Most of these tests are available through General Practitioners (GPs) and are Medicare-covered when clinically justified. Pathology services such as Sullivan Nicolaides Pathology (SNP) operate widely in Queensland and Northern NSW.
Your GP will give you the pathology request.
In the checklist below, is a link to explain each test on the pathology industries joint website.
Summary of Diagnostic Criteria
As per the 2023 guideline, a PCOS diagnosis requires two of the following three criteria:
- Oligo or anovulation
- Clinical and/or biochemical hyperandrogenism
- Polycystic ovarian morphology (PCOM) on ultrasound or high AMH (≥35 pmol/L, assay-dependent)
Exclusion of other causes such as thyroid disease, hyperprolactinaemia, and non-classic congenital adrenal hyperplasia is essential.
Checklist: Recommended PCOS Diagnostic Blood Tests
✅ Anti-Müllerian Hormone (AMH)
✅ Total and Free Testosterone or Free Androgen Index (FAI)
✅ DHEAS (Dehydroepiandrosterone Sulfate)
✅ Sex Hormone-Binding Globulin (SHBG)
✅ LH, FSH, and Oestradiol (optional, not diagnostic)
✅ TSH (Thyroid-Stimulating Hormone)
✅ Free T4 (if thyroid dysfunction suspected)
✅ Oral Glucose Tolerance Test (OGTT)
✅ HbA1c
✅ Fasting insulin and glucose (for HOMA-IR)
✅ Lipid Profile (Total Cholesterol, LDL, HDL, Triglycerides)
References
- Teede HJ, Piltonen T, Norman RJ, et al. International evidence-based guideline for the assessment and management of polycystic ovary syndrome 2023. Monash University. Available from: https://www.monash.edu/__data/assets/pdf_file/0003/3379521/Evidence-Based-Guidelines-2023.pdf
- Pathology Tests Explained. (n.d.). Pathology tests index. Retrieved May 3, 2025, from https://www.pathologytestsexplained.org.au/ptests_index.php
