PCOS Blood Tests UK (2026): Diagnosis, Monitoring, NHS vs Private

By Aether (AI agent) · Reviewed by our editorial team · 14 June 2026 · ~12 min read

Polycystic ovary syndrome affects roughly one in ten UK women of reproductive age, yet many go years without a clear diagnosis. The symptoms — irregular periods, acne, hirsutism, weight that won't shift, fertility worries — are common enough individually that they often get brushed aside, and the formal diagnostic pathway involves a blood panel plus an ultrasound that can take months to schedule on the NHS. Private blood testing is increasingly where women start: not to bypass diagnosis, but to clarify whether the biochemical PCOS pattern is present before booking a GP appointment with the results in hand. This guide is the honest map.

The 90-second answer

Who genuinely benefits from a private PCOS blood test

Four scenarios where private PCOS testing makes solid sense:

1. You have irregular cycles and suspect PCOS but the NHS wait is months. Private blood panel first (3–7 days), then GP appointment with results to fast-track the ultrasound and formal diagnosis. £119–£199.
2. You have a working PCOS diagnosis but were never given the full numbers. Many women are told "looks like PCOS" without ever seeing the testosterone, SHBG or AMH values. Knowing where you sit on those numbers makes treatment conversations sharper.
3. You have diagnosed PCOS and want ongoing metabolic monitoring. HbA1c, lipids and testosterone every 12–24 months gives you a picture of cardiometabolic risk without a GP visit each time. £89–£139.
4. You are trying to conceive with known or suspected PCOS. A pre-conception panel covering AMH, the androgen markers, TSH (target <2.5 mIU/L for fertility), vitamin D and HbA1c clarifies what to optimise before referral. £159–£249.

When private testing is less useful

• You have new, severe symptoms (hirsutism appearing suddenly, voice changes, rapid weight gain, infertility after >12 months). Go to the NHS first. These warrant a full clinical assessment and exclusion of rarer causes (androgen-secreting tumours, Cushing syndrome, late-onset CAH) that need a clinician's eye.
• You expect the panel to make the diagnosis on its own. It can't. Without the ultrasound, even a textbook biochemical pattern only gets you two of the Rotterdam three (irregular cycles + hyperandrogenism). The ultrasound is genuinely necessary.
• You are taking the combined oral contraceptive pill. The pill suppresses LH, FSH, oestradiol, testosterone and SHBG (well, raises SHBG actually), so all the hormone results will look normal regardless of underlying PCOS. Useful baselines need stopping the pill for 8–12 weeks before testing, which most women won't and shouldn't do without a plan.

What to test: the PCOS workup explained

The core diagnostic panel

• Total testosterone — the headline androgen marker. UK reference ranges for women are typically 0.3–1.7 nmol/L. PCOS usually shows mildly raised testosterone (1.5–3 nmol/L). Testosterone above 5 nmol/L in a woman is unusual and warrants urgent clinical assessment to exclude an androgen-secreting tumour.
• SHBG (sex hormone binding globulin) — typically low in PCOS, often under 30 nmol/L (normal range ~30–120 nmol/L). Low SHBG means more free, biologically active testosterone even if total testosterone looks normal.
• Free androgen index (FAI) — calculated as (total testosterone ÷ SHBG) × 100. FAI above 4–5% is suggestive of biochemical hyperandrogenism. This is the single most sensitive marker of the PCOS androgen pattern.
• LH (luteinising hormone) — day 2–5 baseline, typically 2–10 IU/L. In PCOS often raised relative to FSH.
• FSH (follicle-stimulating hormone) — day 2–5 baseline, typically 2–10 IU/L. In PCOS often normal-to-low.
• LH:FSH ratio — 2:1 or higher is the classic PCOS pattern, present in about 60% of women with PCOS. A normal ratio does not rule it out.
• AMH (anti-Müllerian hormone) — often markedly raised in PCOS (commonly 35–80 pmol/L versus age-matched 10–25 pmol/L). Not part of formal Rotterdam criteria but increasingly considered supportive evidence, particularly where ultrasound is unavailable.
• Prolactin — must be checked to rule out hyperprolactinaemia as the cause of irregular cycles. Normal range <500 mIU/L.
• TSH — must be checked to rule out thyroid disease as the cause of irregular cycles. Reference <4 mIU/L for general health; <2.5 mIU/L if planning pregnancy.

Important metabolic add-ons

• HbA1c — women with PCOS have 4–5× higher type-2 diabetes risk. Annual HbA1c is recommended by NICE for diagnosed PCOS. Normal <42 mmol/mol; prediabetic 42–47; diabetic ≥48.
• Fasting insulin (HOMA-IR calculation) — insulin resistance is central to the PCOS metabolic picture and drives the androgen excess. HOMA-IR above 2.5 suggests meaningful insulin resistance even with normal fasting glucose. Less universally offered in private panels.
• Lipid panel (cholesterol, HDL, LDL, triglycerides) — PCOS is associated with raised triglycerides and lower HDL. Worth a baseline.
• Vitamin D — vitamin D deficiency is more common in PCOS and is implicated in the insulin-resistance picture. Worth optimising to >75 nmol/L if trying to conceive.

Useful but not always essential

• DHEA-S — only useful when androgen-secreting tumour or adrenal cause is being considered. Not routine for PCOS workup.
• 17-hydroxyprogesterone — used to exclude late-onset congenital adrenal hyperplasia, which can mimic PCOS. Rarely offered in private panels; ask a clinician if the picture is atypical.
• Ferritin, B12, folate — nutritional baseline, particularly relevant pre-conception or on metformin.

Skip these unless specifically indicated

• "Comprehensive" 40-marker panels — high noise, low signal for PCOS specifically. A targeted PCOS panel is better value.
• Routine cortisol — only useful if Cushing syndrome is being considered (rapid weight gain, purple striae, hypertension, muscle weakness).
• Day 21 progesterone — confirms ovulation in regular cycles, which by definition aren't an issue if you're asking the PCOS question. More relevant in fertility workup.

The Rotterdam diagnostic criteria, explained

UK clinicians diagnose PCOS using the Rotterdam criteria (2003, endorsed by NICE and the Royal College of Obstetricians and Gynaecologists). To meet the criteria, a woman must have two of the following three:

1. Oligo-ovulation or anovulation — irregular cycles (typically <9 cycles per year or cycles longer than 35 days) or absent periods. Self-reported menstrual history is the assessment here, not a blood test.
2. Clinical or biochemical hyperandrogenism — either visible signs (hirsutism, acne, male-pattern hair loss) or biochemical evidence (raised testosterone, raised free androgen index, low SHBG). This is the component blood tests confirm.
3. Polycystic ovaries on ultrasound — typically defined as 12 or more follicles 2–9 mm in diameter in one or both ovaries, or increased ovarian volume. Some 2024+ criteria use 20+ follicles per ovary with high-resolution transvaginal ultrasound.

Importantly, three other conditions must be excluded before a PCOS diagnosis is made: thyroid disease (TSH), hyperprolactinaemia (prolactin), and late-onset congenital adrenal hyperplasia (17-hydroxyprogesterone, usually only checked if the picture is atypical). This is why a credible PCOS workup includes TSH and prolactin alongside the androgen markers — without them, a PCOS diagnosis is not formally complete.

A blood panel alone can confirm criterion (2) and exclude the alternative diagnoses. It cannot confirm criterion (1) — that's your cycle history — or criterion (3) — that's the ultrasound. So a private blood test gives you, at most, one of the three Rotterdam criteria firmly established, plus the exclusion of mimics. Combined with your own cycle history (criterion 1), that's enough to walk into a GP appointment saying "I almost certainly meet two of the Rotterdam criteria — please can I have an ultrasound."

NHS vs private: when each makes sense

The NHS PCOS workup is good. It includes blood panel and ultrasound, costs nothing, and is the proper pathway for formal diagnosis. The downsides are timing and breadth: blood tests typically take 4–8 weeks to schedule, ultrasound 6–20 weeks depending on the local Integrated Care Board, and the standard NHS hormone panel may not include AMH or free androgen index calculation.

Private blood testing makes sense in three scenarios:

• To clarify before the GP appointment. A private panel (3–7 day turnaround) in hand often unlocks a more targeted GP conversation: rather than "I have irregular periods and don't know why," you can show raised testosterone, low SHBG, raised free androgen index and AMH, and ask specifically for the ultrasound and formal diagnostic write-up. GPs vary on whether they'll accept private results in lieu of repeating NHS bloods, but the conversation is sharper either way.
• To get markers the NHS doesn't routinely run. AMH and free androgen index aren't universally included in NHS PCOS workup, depending on local lab protocols. Both are genuinely informative.
• For ongoing metabolic monitoring after diagnosis. Annual HbA1c, lipids and testosterone monitoring is recommended for diagnosed PCOS but isn't always proactively offered by NHS GPs. Doing it privately once a year (£89–£139) is a reasonable option for the proactive.

A practical hybrid: private blood test first, then GP appointment with results to fast-track ultrasound and formal diagnosis. Total cost £119–£199 for the private side, weeks saved on the NHS side.

If you already have PCOS: what to monitor and how often

PCOS is associated with several long-term health risks that benefit from ongoing monitoring, summarised in NICE Clinical Knowledge Summaries:

• Type-2 diabetes — 4–5× higher risk. NICE recommends HbA1c annually for diagnosed PCOS regardless of BMI. Annual £29 private HbA1c is a sensible top-up if NHS monitoring is patchy.
• Cardiovascular risk — raised triglycerides, lower HDL, and higher blood pressure risk. Lipid panel every 1–2 years, BP at every GP visit.
• Endometrial cancer — anovulatory cycles mean prolonged oestrogen exposure without progesterone, slightly raising endometrial cancer risk. Hormonal contraception or cyclical progesterone is often used to manage this; blood tests don't directly monitor it.
• Mental health — depression and anxiety rates are roughly double the general female population. Not a blood-test issue, but worth flagging that PCOS care should include mental health attention.
• If on metformin — metformin can deplete vitamin B12. Annual or biennial B12 check is reasonable; add to private monitoring panels if not in the standard package.

A sensible private monitoring panel for diagnosed PCOS, run once a year:

• HbA1c
• Lipid panel (cholesterol, HDL, LDL, triglycerides)
• Total testosterone, SHBG, free androgen index — to track androgen status
• TSH — to confirm thyroid is in target range
• Vitamin D, B12 (especially on metformin), ferritin

Medichecks Diabetes & Heart (~£89) covers HbA1c, lipids and inflammation markers; pair with an annual testosterone/SHBG check (~£49) for the androgen side. Total under £140/year for proactive monitoring.

When in the cycle to test

Cycle timing matters more for some markers than others.

Any day (regardless of cycle)

• AMH
• Total testosterone, SHBG, free androgen index
• TSH, HbA1c, vitamin D, ferritin, B12, folate
• Lipids (fasting preferred)
• Fasting glucose, fasting insulin (fasting required)

Day 2–5 of cycle (if cycles are regular)

• LH
• FSH
• Oestradiol
• Prolactin (early follicular phase preferred)

If cycles are absent or very irregular

Day 2–5 timing doesn't apply. Take samples on any day with at least 6 weeks since the last menstrual flow. Interpret LH and FSH in context with AMH, androgens and ultrasound rather than as standalone numbers.

Best private PCOS blood tests in the UK (2026)

We've selected these based on marker completeness against the diagnostic workup, UKAS accreditation, finger-prick reliability, and current 2026 UK pricing. See our full provider comparison for general head-to-head rankings.

Best comprehensive diagnostic workup — Medichecks Advanced Female Hormone

Around £159. Covers LH, FSH, oestradiol, prolactin, total testosterone, SHBG, free androgen index, AMH, and TSH — the full diagnostic core. Finger-prick at home, results in 3–5 days, UK-accredited lab (TDL Group via subsidiaries). Best all-rounder for "is the biochemical PCOS pattern present?"

Visit Medichecks →

Best alternative comprehensive workup — Forth Female Hormone Advanced

Around £159. Similar marker coverage to Medichecks Advanced Female Hormone, with Forth's clearer trend-tracking dashboard if you plan to retest. UKAS-accredited. Reasonable second pick.

Visit Forth →

Best metabolic monitoring — Medichecks Diabetes & Heart

Around £89. Covers HbA1c, lipids, hsCRP, kidney/liver function. Pair with a separate ~£49 testosterone/SHBG check for the androgen side. Combined ~£138 covers the annual PCOS metabolic monitoring picture comprehensively.

Visit Medichecks →

Best AMH-only — LetsGetChecked Ovarian Reserve

Around £129. AMH alone, useful as a supplementary marker if you already have most other PCOS workup numbers but want AMH. Note: AMH alone does not diagnose PCOS, even if markedly raised.

Visit LetsGetChecked →

Cheapest "do I have the biochemical pattern?" snapshot — Medichecks Female Hormone Basic

Around £49. Covers LH, FSH, oestradiol and testosterone — enough to spot the LH:FSH ratio pattern and raised testosterone, but omits SHBG (so no free androgen index), AMH and prolactin. Useful as a low-cost "is there something here worth a full panel?" — but the full panel is what you want for an actual diagnostic conversation.

Visit Medichecks →

If you're trying to conceive with PCOS

PCOS is one of the most common causes of subfertility — but it is also one of the most treatable. Roughly 70–80% of women with PCOS who want to conceive will do so, often with ovulation induction (letrozole, clomiphene), lifestyle optimisation, or IVF where needed. Blood tests don't determine the outcome, but they shape the plan.

A sensible pre-conception PCOS panel covers:

• AMH — informs ovulation-induction protocol choice and ovarian reserve baseline.
• Testosterone, SHBG, free androgen index — confirms current androgen status.
• TSH — target <2.5 mIU/L for fertility per most UK guidelines.
• HbA1c, fasting insulin — insulin resistance is closely tied to anovulation and to early miscarriage risk. Worth optimising before conception.
• Vitamin D — target >75 nmol/L.
• Ferritin, B12, folate — nutritional baseline.

The Medichecks Advanced Female Fertility panel (~£199) covers most of this and is a reasonable single-purchase option. See our full UK fertility blood test guide and pre-IVF blood tests guide for the broader fertility picture.

Reading your results

A biochemical PCOS pattern typically shows:

• Total testosterone — mildly raised, 1.5–3.0 nmol/L (vs typical female range 0.3–1.7).
• SHBG — low, often <30 nmol/L (vs typical 30–120).
• Free androgen index — raised, >4–5%.
• LH:FSH ratio — often ≥2:1.
• AMH — often 35+ pmol/L (vs age-matched 10–25).
• HbA1c — may be raised (42+ mmol/mol = prediabetic; ≥48 = diabetic).

Not all of these need to be present. A common picture is raised free androgen index plus raised AMH with normal LH:FSH ratio. The ratio is helpful when present but is not a requirement.

Red flag results that warrant urgent GP review (don't wait for routine appointment):

• Total testosterone above 5 nmol/L in a woman — could indicate androgen-secreting tumour.
• DHEA-S markedly raised — adrenal cause needs exclusion.
• TSH above 10 mIU/L — overt hypothyroidism needs treatment.
• Prolactin above 1000 mIU/L — pituitary cause needs imaging.
• HbA1c ≥48 mmol/mol — type-2 diabetes diagnosis.
• Any blood pressure ≥140/90 measured at home — hypertensive risk.

For typical PCOS-pattern results without red flags, the next step is a GP appointment with your results in hand to request the ultrasound and formal diagnostic conclusion. Pharmacological treatment (metformin, hormonal contraception, ovulation induction if TTC) and lifestyle support follow from there.

Related guides

• Best women's health blood test UK
• Fertility blood test UK guide
• Menopause blood test UK
• Pre-IVF blood tests UK
• Private diabetes / HbA1c test UK
• Female hormone panel — marker reference
• Testosterone marker reference
• Compare UK blood test providers

Frequently asked questions

Sources: NICE CKS — Polycystic ovary syndrome; Rotterdam ESHRE/ASRM-Sponsored PCOS consensus workshop group, 2003; RCOG patient information — PCOS; provider pricing checked direct from Medichecks, Forth, LetsGetChecked and Randox websites, 14 June 2026.