The complete set of biomarkers needed for PCOS diagnosis and management including testosterone, SHBG, insulin resistance markers, and why standard GP testing misses the metabolic root of the condition.
PCOS (polycystic ovary syndrome) diagnosis and management requires testing testosterone, free androgen index, SHBG, LH, FSH, fasting insulin, HOMA-IR, HbA1c, DHEA-S, cortisol, thyroid function, and inflammation markers together. GPs typically only check total testosterone and perform an ultrasound, missing the metabolic and hormonal picture that determines the type of PCOS and guides effective treatment. The TrueVitals Ultimate panel covers every one of these markers as part of a 110-biomarker panel for £349.
PCOS affects approximately 1 in 10 women in the UK and is the most common endocrine disorder in women of reproductive age. Yet despite being so prevalent, it remains one of the most poorly investigated conditions in primary care. Most women with PCOS report years of dismissed symptoms before receiving a diagnosis, and even once diagnosed, the standard approach of "lose weight and take the pill" fails to address the underlying hormonal and metabolic drivers.
The reason GP testing falls short is that PCOS is not a single condition. It is an umbrella term covering at least four distinct types, each driven by different root causes. Without comprehensive testing, your GP cannot determine which type you have — and therefore cannot recommend effective treatment.
The four types of PCOS and the markers that identify them:
Insulin-resistant PCOS is the most common type, affecting approximately 70% of women with the condition. Elevated fasting insulin and a HOMA-IR above 2.0 confirm insulin resistance, which drives the ovaries to produce excess androgens. Fasting glucose and HbA1c may be completely normal even when insulin is significantly elevated, which is why standard GP testing misses this entirely. If your GP only checks glucose, they will tell you your blood sugar is fine while your pancreas is working overtime and your ovaries are being stimulated to overproduce testosterone.
Inflammatory PCOS is driven by chronic low-grade inflammation that stimulates ovarian androgen production. Elevated hs-CRP, elevated ESR, or elevated white blood cell count alongside elevated androgens and normal insulin suggests this type. Gut dysfunction, food sensitivities, environmental toxins, and stress can all drive the inflammatory picture. Treatment focuses on anti-inflammatory nutrition, gut health, and stress management rather than the standard insulin-focused approach.
Adrenal PCOS is characterised by elevated DHEA-S with normal or only mildly elevated testosterone. The excess androgens come from the adrenal glands rather than the ovaries, often driven by chronic stress. Cortisol testing is essential here — elevated cortisol alongside elevated DHEA-S confirms adrenal hyperactivity. This type does not respond to metformin or the oral contraceptive pill in the same way as insulin-resistant PCOS.
Post-pill PCOS occurs when androgen levels temporarily spike after stopping hormonal contraception. LH and FSH testing helps identify this type — a high LH-to-FSH ratio alongside elevated androgens in a woman who recently stopped the pill suggests a temporary hormonal readjustment rather than true PCOS. This type often resolves within 3-12 months without treatment.
What your GP actually tests:
A typical GP investigation for suspected PCOS includes total testosterone (without SHBG or free androgen index), possibly LH and FSH, glucose or HbA1c (but not fasting insulin or HOMA-IR), and a pelvic ultrasound. This approach can confirm the Rotterdam criteria for diagnosis but cannot identify which type of PCOS you have or what is driving it.
What you actually need tested:
Total testosterone AND SHBG AND free androgen index — because total testosterone alone does not reflect bioavailable androgens. A woman with a total testosterone of 2.0 nmol/L and an SHBG of 20 has much more bioavailable testosterone than a woman with the same total testosterone and an SHBG of 80.
Fasting insulin AND HOMA-IR — because insulin resistance is the root cause in 70% of PCOS cases and is invisible to glucose and HbA1c testing until it has progressed significantly.
DHEA-S — to differentiate ovarian from adrenal androgen excess. This single marker changes the entire treatment approach.
Cortisol — to identify stress-driven adrenal PCOS and to understand the HPA axis contribution to the hormonal picture.
LH and FSH with LH:FSH ratio — an elevated ratio above 2:1 or 3:1 is characteristic of PCOS and helps confirm the diagnosis. FSH alone also helps assess ovarian reserve.
Full thyroid panel including TSH, Free T4, Free T3, and antibodies — because hypothyroidism mimics many PCOS symptoms (weight gain, fatigue, irregular periods, hair loss) and the two conditions frequently coexist. Hashimoto's thyroiditis is more common in women with PCOS.
Inflammation markers (hs-CRP, ESR) — to identify inflammatory PCOS and guide anti-inflammatory interventions.
Prolactin — elevated prolactin can cause symptoms that overlap with PCOS and should be ruled out.
Vitamin D — deficiency is significantly more common in women with PCOS and supplementation has been shown to improve insulin sensitivity and androgen levels.
The TrueVitals Ultimate panel tests every one of these markers plus a complete metabolic profile, liver function, kidney function, iron studies, full blood count, cancer markers, immunoglobulins, and urinalysis — 110 biomarkers in total. The 60-page personalised report identifies which PCOS type your results suggest and provides targeted supplement and lifestyle recommendations specific to your pattern.
See what a real TrueVitals report looks like →