When PCOS is suspected, you mainly look at testosterone, SHBG, LH, FSH and, if needed, DHEA-S and AMH. No single value proves PCOS on its own; together they show a pattern that fits. The best time to test is usually in the first days of your cycle.
I notice that women often arrive with one number in mind: their testosterone. But you do not read PCOS from a single value. Below you go through each hormone, what it shows, when to measure it and what a result does and does not mean.
Which hormones do you test for PCOS?
A PCOS workup revolves around the androgens (male hormones) and the hormones that steer your cycle. Together they give a picture of why ovulation fails to happen and how many androgens are circulating.
- Total testosterone measures all the testosterone in your blood. A raised value fits the PCOS picture.
- Free testosterone is the part that is actively available. It can be raised while your total testosterone looks normal.
- SHBG binds testosterone. A low SHBG makes more testosterone freely available, and is often lowered in PCOS.
- LH and FSH steer your cycle. A raised LH/FSH ratio often fits PCOS.
- DHEA-S shows whether the adrenal glands contribute to the androgens.
- AMH is often raised in PCOS due to the many small follicles.
Prolactin is often included too, not because it belongs to PCOS, but to rule out another cause of a disrupted cycle. The full overview of symptoms and diagnosis is in our PCOS pillar.
When is the best time to test?
The best time to have your hormones drawn is in the first days of your cycle, usually day 2 to 5. In that phase LH, FSH and oestradiol are at their baseline, which makes the comparison more reliable.
Do you have no period or a very irregular one? Then there is no fixed cycle to anchor to, and blood can be drawn at any time. This is common in PCOS exactly because the cycle is unpredictable. Testosterone, SHBG and DHEA-S depend less on the cycle day.
A practical tip: test in the morning. Some hormones, like testosterone, are then at their highest and best compared with reference values.
How do you read a PCOS result?
You always read a result alongside the reference range, your complaints and your cycle day. A value just outside the range does not automatically mean PCOS, and a normal value does not fully rule it out. It is about the combination.
A pattern that often fits PCOS:
- A raised total or free testosterone
- A lowered SHBG
- An LH that is higher than FSH
- Sometimes a raised AMH
Still, this is not a checklist you tick off yourself. PCOS is established with the Rotterdam criteria, where two of the three points are needed, and other causes are ruled out first. Unsure about your signals? Then first read how to recognise PCOS symptoms.
In one test: the Hormones Women
Separate values say little, the pattern says everything. So the Hormones Women panel measures testosterone, SHBG, LH, FSH and prolactin in one draw. That way you get the whole picture rather than an isolated number.
Want to map your egg reserve or wish to conceive alongside your hormones? Then the Fertility Assessment looks at AMH, FSH and LH among others. Which test suits your situation depends on your question and your complaints.
You need a referral for neither. You test at a location near you and receive your result digitally, with an assessment per value by a BIG-registered doctor.
Frequently asked questions
Which hormone matters most in PCOS?
Testosterone gets the most attention, because it explains the androgenic complaints. Yet you rarely read it alone: SHBG, LH and FSH give it meaning. It is about the pattern, not one value.
Can my testosterone be normal while I still have PCOS?
Yes, it can. Sometimes your total testosterone is normal while your free testosterone is raised, because your SHBG is low. That is why they are read together, alongside your complaints.
Do I have to test on a particular cycle day?
With a regular cycle, day 2 to 5 is most common. If you have no fixed cycle, blood can be drawn at any time. When in doubt, discuss with a doctor what fits.
References
- Teede HJ, Tay CT, Laven J, et al. International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome 2023. Monash University, ESHRE and ASRM, 2023.
- Rotterdam ESHRE/ASRM-Sponsored PCOS Consensus Workshop Group. Revised 2003 consensus on diagnostic criteria and long-term health risks related to polycystic ovary syndrome (PCOS). Hum Reprod. 2004;19(1):41-47.
- NHG and Thuisarts.nl. Polycystic ovary syndrome (PCOS). Dutch College of General Practitioners. Available via thuisarts.nl.
Every blood test result through Lunara includes a professional assessment by a BIG-registered doctor. For treatment decisions, discuss your results with your GP.
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