Hormones . Symptoms guide
PMOS (formerly PCOS) Symptoms: What to Test First
Quick answer
Polyendocrine Metabolic Ovarian Syndrome (PMOS) is the new official name for the hormonal and metabolic condition previously called Polycystic Ovary Syndrome (PCOS). It affects roughly 1 in 8 women worldwide (around 170 million). PMOS presents diversely: many experience elevated androgens (driving acne and hair changes), but a significant cohort features the non-androgenic phenotype, presenting with irregular cycles and polycystic ovaries on ultrasound despite normal blood androgen levels. Diagnosis is clinical, requiring two of three features (irregular cycles, hyperandrogenism, polycystic ovaries on scan). Bloodwork supports the diagnostic process by quantifying testosterone and SHBG to calculate the Free Androgen Index, while markers like LH and FSH are measured primarily to rule out alternative causes of absent periods (such as POI or hypothalamic amenorrhoea) rather than as positive diagnostic benchmarks for PMOS itself. Metabolic markers we actually measure are HbA1c, fasting insulin and the calculated HOMA-IR index, rather than true insulin sensitivity (which requires specialist dynamic testing such as a euglycaemic clamp or oral glucose tolerance test). The renaming was announced in May 2026 by the Society for Endocrinology as part of a global effort through the International PCOS Network, to move the name away from "ovarian cysts" and reflect the actual hormonal and metabolic nature of the condition.
This patient information is being clinically reviewed by our team. The factual content draws on UK guidance (NHS, NICE, British Association of Dermatologists, and other specialist society guidance where cited).
Understanding your phenotype
- PMOS (hyperandrogenic phenotype). Raised androgens with irregular cycles. Free Androgen Index (from testosterone and SHBG) is the key serum marker.
- PMOS (metabolic phenotype). Insulin resistance with raised androgens. HbA1c, fasting insulin and HOMA-IR capture this.
- PMOS (non-androgenic phenotype). Irregular cycles and polycystic ovaries on scan with normal blood androgens.
- Differential: thyroid dysfunction, prolactinoma, congenital adrenal hyperplasia, POI, hypothalamic amenorrhoea. Bloodwork (including LH and FSH for exclusionary purposes) rules these out.
Red flags that warrant urgent endocrinology / gynaecology referral
Rapid-onset virilisation appearing over weeks (rather than the slow, years-long change typical of PMOS) is a classic red flag for a rare androgen-secreting adrenal or ovarian tumour rather than standard PMOS. This is not a 999 emergency but it does warrant an expedited specialist referral rather than waiting for routine blood-panel results. Ask your GP for an urgent endocrinology or gynaecology referral.
- Rapid-onset virilisation: severe facial hair growth appearing over weeks rather than years
- New voice deepening
- Clitoromegaly
- Rapid muscle bulking or new male-pattern frontal hairline regression alongside the above
Common features that suggest this
- Irregular or absent periods
- Acne (especially jawline)
- Hirsutism (face, chest, abdomen)
- Scalp hair thinning
- Difficulty losing weight
- Insulin resistance signs (skin tags, acanthosis nigricans)
Recommended tests
Same-day appointments at our Harley Street clinic, results clinician-reviewed.
Need a marker not in these panels? Build a custom panel and a GMC-registered clinician will design one for you.
Markers your clinician will commonly look at
These are the individual blood markers in the recommended panels above. Click any to read what it measures, its UK reference range, and what high or low values mean.
Testing advice
Days 2 to 5 of the cycle if you still bleed regularly. If cycles are absent, any day is acceptable. Morning appointment. Important: if you are on the combined contraceptive pill, you must be off the pill completely for at least 3 months before a diagnostic hormone panel; the 7-day pill-free interval is not sufficient because residual medication continues to suppress LH, FSH, oestrogen and testosterone.
Common questions
Can I test for PMOS if I am on the contraceptive pill?
Critical testing rule: if you are looking for a formal hormonal diagnosis, you cannot test accurately while taking the pill. The medication intentionally shuts down your natural ovarian hormone production. The pill-free week fallacy: testing during your 7-day pill break is invalid; your LH, FSH, oestrogen and total testosterone will remain suppressed by the residual medication and the result is uninterpretable. A true diagnostic baseline requires being completely off the pill for at least 3 months. What you can test now: if you do not wish to stop your medication, you can still safely test the metabolic markers (HbA1c, fasting insulin and lipid profiles), which provide vital context on the metabolic side of the syndrome.
Does PMOS (formerly PCOS) cause hair loss?
Yes. Elevated levels of circulating male hormones (androgens), a core feature of several PMOS phenotypes, can bind to hair follicles on the scalp. This causes a process called follicular miniaturisation, leading to female pattern hair thinning, typically along the parting or crown. Our Advanced Hair and Hormone Check is specifically designed to isolate these androgenic markers alongside crucial nutritional co-factors like ferritin and vitamin D that accelerate shedding.
Is PMOS the same as PCOS?
Yes, they are identical. Polyendocrine Metabolic Ovarian Syndrome (PMOS) is the updated clinical name for Polycystic Ovary Syndrome (PCOS), introduced to better reflect that this is a systemic metabolic and hormonal condition, not a disease of "ovarian cysts". Because the global transition to this new terminology is progressive, you will see both terms used interchangeably across the NHS, specialist clinics, and our own testing panels over the coming years. Your diagnostic criteria and treatment pathways remain exactly the same.
Related symptoms
Sources and further reading
- NICE CKS: Polycystic ovary syndrome
- Society for Endocrinology: PMOS is the new name for PCOS (May 2026)
This page provides general information only and is not a substitute for medical advice. A GMC-registered clinician will review your results and tailor any recommendations to you personally.