PMOS (polyendocrine metabolic ovarian syndrome) is the new name for what was previously called PCOS (polycystic ovary syndrome). It was formally adopted following an international expert consensus published in The Lancet in May 2026. Same condition, updated name that better reflects its complexity as a whole-body metabolic and hormonal condition.

Why was PCOS renamed PMOS?

The old name implied the presence of ovarian cysts, which is inaccurate. PMOS reflects that it is a complex polyendocrine and metabolic condition, not primarily a gynaecological one. The rename aims to improve diagnosis, public understanding, and whole-body care for women with the condition.

Is PMOS the same as PCOS?

Yes. PMOS and PCOS are the same condition — PMOS is simply the updated name. All previous PCOS diagnosis, research, and treatment guidance applies to PMOS. If you have a PCOS diagnosis, nothing about your condition or treatment changes as a result of the rename.

Does PMOS always involve ovarian cysts?

No. What appear as cysts on ultrasound are actually arrested follicles — immature eggs that did not develop fully. PMOS is driven by hormone imbalances and insulin resistance, not ovarian cysts. Many women with PMOS do not have the appearance of polycystic ovaries at all.

PCOS PMOS

PMOS (formerly PCOS) Explained: Why It Was Never About Ovarian Cysts

TribeTeam

September 7, 2025

Updated 21 May 2026

PCOS has been officially renamed PMOS

The Lancet formally adopted the new name — polyendocrine metabolic ovarian syndrome (PMOS) — in May 2026. Read the Lancet paper →

Reviewed by Julie Boora, Superintendent Pharmacist, TribElle Health Ltd (GPhC Reg. 9012688) · Updated 21 May 2026

Polycystic ovary syndrome (PCOS) — now officially called PMOS — is one of the most misunderstood conditions in women's health. Despite the name, PCOS was never really about having "polycystic" ovaries. Those small fluid-filled sacs seen on ultrasound aren't true cysts at all. They're immature follicles that never developed properly.

The real story? PMOS is driven by hormone imbalances — especially excess androgens (male-type hormones) and insulin resistance. These two factors create a feedback loop that explains why PMOS causes irregular periods, acne, excess hair growth, fertility struggles, and metabolic problems.

Let's break down the science, and the latest evidence, so you can see what's really happening in your body and why.

Myth-busting the name: PMOS isn't about cysts

The Lancet rename formally validates something clinicians and patients have long known. PMOS is now the global standard term. Here's why the old name was misleading:

→	In PMOS, the ovaries contain many small follicles (undeveloped eggs)

→	They look like "cysts" on ultrasound, but they're not dangerous or cancerous

→	These follicles build up because ovulation doesn't occur regularly

Key point: The ovaries look "polycystic" because of hormone disruption — not the other way around.

Core driver 1: excess androgens

One of the defining features of PMOS is hyperandrogenism — higher-than-normal levels of hormones like testosterone and androstenedione.

→	Androgens disrupt follicle maturation — no dominant egg develops

→	No ovulation = irregular or missed periods

→	High androgen levels also cause acne, hirsutism (excessive facial or body hair), and scalp hair thinning

Ovarian theca cells (the hormone-producing cells around follicles) are unusually sensitive in PMOS, producing excess androgens even in response to normal signals. NHS: PMOS symptoms and causes

Core driver 2: insulin resistance

Here's where PMOS goes beyond reproductive health into metabolism.

→	Insulin resistance means cells don't respond properly to insulin

→	To compensate, the body makes more insulin (hyperinsulinemia)

→	High insulin stimulates the ovaries to produce more androgens

→	High insulin lowers SHBG (sex hormone binding globulin) → more free testosterone circulates in the blood

Key point: PMOS can affect women of all body types. Many lean women also have insulin resistance — although it's more common and more severe in those who are overweight.

NIH: PCOS and insulin resistance

The vicious cycle: insulin and androgens

This is why PMOS symptoms often reinforce one another:

1	Insulin resistance → high insulin
2	High insulin → ovaries make more testosterone
3	More testosterone → ovulation is disrupted → follicles accumulate in ovaries
4	Disrupted ovulation → worsens hormone imbalance
5	More androgens + weight changes → worsen insulin resistance

LH/FSH imbalance adds fuel

Normally, the brain releases LH (luteinising hormone) and FSH (follicle-stimulating hormone) in balance. In PMOS:

→	LH levels are often higher relative to FSH

→	High LH → more ovarian androgen production

→	Low FSH → follicles don't mature properly

→	The result = irregular or absent ovulation

This is why PMOS is strongly linked to infertility. Read our guide on GLP-1, PCOS, and fertility →

Beyond periods and fertility

The PMOS rename specifically exists to foreground these metabolic dimensions. Because PMOS affects multiple systems, its impact goes well beyond the ovaries.

Metabolic health 1 in 8 women with PMOS has insulin resistance. Over half will develop prediabetes or type 2 diabetes by age 40.	Heart health Higher rates of cholesterol problems, high blood pressure, and metabolic syndrome.
Endometrial cancer risk Irregular ovulation means unopposed oestrogen, which can cause endometrial thickening over time.	Mental health Higher rates of anxiety and depression, often linked to symptoms like weight changes, infertility, and hirsutism.

Mayo Clinic: PCOS overview

Guideline update: what's changed

The 2013 Endocrine Society Guideline is now retired. In 2023, a new International Evidence-Based PCOS Guideline was released, endorsed by the Endocrine Society, ASRM, ESHRE, and others.

Key updates from the 2023 guideline

Diagnosis now requires two of three:

1	Clinical or biochemical androgen excess

2	Ovulatory dysfunction

3	Polycystic ovaries on ultrasound or elevated AMH levels (in adults, AMH can replace ultrasound)

→	The guideline recognises PMOS as a lifelong condition with metabolic, reproductive, and psychological implications

→	Care should include screening for metabolic and mental health risks, lifestyle support, and shared decision-making

2026 update: PCOS is now PMOS

→	Polycystic Ovary Syndrome (PCOS) has been renamed Polyendocrine Metabolic Ovarian Syndrome (PMOS) following international expert consensus

→	The name change reflects that the condition is not just a reproductive disorder, but a complex condition affecting multiple body systems

→	The new name better reflects links to hormonal imbalance, insulin resistance, metabolic health, cardiovascular risk, and mental wellbeing

→	PMOS is a lifelong endocrine and metabolic condition — not simply a reproductive syndrome

Read the Lancet paper on PMOS →

2023 International PCOS Guideline — Monash University · European Journal of Endocrinology

The takeaway

→	The exact cause of PMOS is still not fully understood

→	PMOS is not about cysts — it's about hormone disruption

→	Excess androgens and insulin resistance drive most symptoms, feeding into each other in a cycle

→	The 2023 guideline recognises PMOS as a systemic, lifelong condition

→	PCOS was formally renamed PMOS in 2026

Treatments focus on:

→	Improving insulin sensitivity (lifestyle, metformin, inositol)

→	Reducing androgens (hormonal contraceptives, anti-androgens, weight management)

→	Supporting ovulation for fertility

Frequently asked questions

Final word from TribElle

PMOS is common, complex, and often misunderstood. By breaking the silence and explaining the science, we can give women clarity and confidence. Your symptoms are not your fault.

With the right support — clinical care, nutrition, and sometimes medication — PMOS is manageable, and your health and goals are still within reach. The renaming is a validation of what women have long known: this condition was always bigger than its name suggested.