PMOS (Polyendocrine Metabolic Ovarian Syndrome) is the new international name for PCOS, adopted in May 2026 by the Endocrine Society. It is the most common endocrine disorder in women of reproductive age, affecting 1 in 8 women (≈170 million worldwide). Diagnosis requires 2 of 3 Rotterdam criteria: irregular cycles, hyperandrogenism, or polycystic ovarian morphology.

What is the difference between PCOS and PMOS?

PCOS (Polycystic Ovary Syndrome) and PMOS (Polyendocrine Metabolic Ovarian Syndrome) refer to exactly the same medical condition. The May 2026 renaming by the Endocrine Society and The Lancet removes the misleading "cysts" reference — absent in 30% of patients — and emphasises the metabolic and endocrine nature of the syndrome. Diagnostic criteria remain unchanged.

What are the symptoms of PMOS / PCOS?

Main symptoms include: irregular or absent periods (oligo-anovulation), signs of excess androgens (acne, hirsutism, hair loss), difficulty conceiving, insulin resistance (present in 50–80% of cases regardless of weight), and polycystic ovarian morphology on ultrasound. Brain fog, fatigue, and mood disorders are also frequently reported.

Does PMOS / PCOS prevent pregnancy?

No. PMOS is the leading cause of anovulatory infertility, but effective treatments exist. Letrozole (first-choice per ESHRE 2023) induces ovulation in 70–80% of cases. The majority of women with PMOS achieve pregnancy naturally or after treatment.

What treatments exist for PMOS / PCOS in 2026?

Validated options in 2026 include: lifestyle measures (anti-inflammatory diet, exercise), myo/D-chiro inositol (40:1 ratio), metformin (insulin resistance), combined oral contraceptive (cycles + androgens), letrozole (fertility), spironolactone (hirsutism). GLP-1 agonists (semaglutide, tirzepatide) are approved for PMOS with BMI ≥ 30 since May 2026.

PCOS has a new international name since May 2026

Understanding and living with PCOS / PMOS

Identify your phenotype in 4 minutes · Decode your lab results · ESHRE 2023 guidelines · Free tools

Phenotype

A, B, C or D? Find your Rotterdam profile

Symptoms

Cycles, androgens, insulin, PCOM

2026 Research

Retatrutide, tirzepatide, microbiome, inositol

Myths busted

PCOS ≠ obesity · ≠ infertility · ≠ lifelong

Identify my phenotype Understand the new name

~4 minutes · No registration · Your answers stay in your browser.

1 in 8

women
affected

70 %

un-
diagnosed

3-5 yrs

avg. time to
diagnosis

Interactive demo

What happens in your cycle

Visualize in real time the difference between a normal cycle and a PCOS cycle — and understand why LH and FSH hormones play a central role.

Animated hormone cycle

Visualize the difference between a normal cycle and a PCOS/PMOS cycle

LHFSHEstradiolProgesterone

Understand the role of insulin resistance in PCOS

You are not alone

1 in 8

women worldwide, ~170 million (Endocrine Society, 2026)

0 %

remain undiagnosed (WHO, 2023)

3-5 yrs

average time to diagnosis (Monash, 2023)

~0 %

report regular brain fog (JCEM, 2023)

Detailed sources: scientific sources

What readers say

“The hormone chart finally helped me understand why my cycles are so irregular. I showed it to my doctor and she said it was a perfect starting point.”

A. M. — London

“I used the doctor prep tool before my appointment and for the first time I felt truly heard. My GP actually read the whole summary I printed.”

S. K. — Toronto

“Four years with PCOS without understanding what was happening. This site explained everything in plain language with real scientific references.”

L. R. — Sydney

Reader testimonials · Names abbreviated for privacy

Tools

Four essential tools, no sign-up

Your answers stay in your browser. No account needed. Everything downloads as a PDF you can take to your doctor.

My PCOS / PMOS summary

A 7-step guided journey to prepare a clear summary of your situation, ready to share with your doctor.

~10 minutes
Print-ready PDF

Start

Letter for my doctor

A structured one-page PDF in 5 minutes — symptoms, labs, treatments tried. Your doctor reads it in 30 seconds.

~5 minutes
Download PDF

Start

Symptom checker

12 questions to spot the most common signs — not a diagnosis, but a basis for discussion with your clinician.

~3 minutes
Instant result + PDF

Start

HOMA-IR calculator

Your insulin-resistance index from fasting glucose and insulin, with a cautious interpretation panel.

~30 seconds
Score + interpretation

Start

The renaming

Why a new name?

1935

First description

Stein and Leventhal describe the syndrome in 7 women.

1990

NIH consensus

First formal diagnostic criterion.

2003

Rotterdam criteria

3 ESHRE/ASRM criteria. 4 phenotypes (A, B, C, D).

2023

International guideline

Monash + ESHRE update: AMH can replace ultrasound.

2026

PMOS renaming

The Lancet + Endocrine Society + 56 organizations: Polyendocrine Metabolic Ovarian Syndrome.

For decades, this syndrome was reduced to a problem of “polycystic ovaries.” Yet many people affected do not actually have true cysts, and primarily experience hormonal, metabolic, skin-related, psychological, and fertility-related symptoms.

On 12 May 2026, an international consensus published in The Lancet, led by the Endocrine Society and the team at Monash University, officially introduced a new name: PMOS — Polyendocrine Metabolic Ovarian Syndrome.

According to the Endocrine Society, this syndrome affects approximately 1 in 8 women — over 170 million people worldwide. The WHO estimates its prevalence at 10–13% of women of reproductive age, with up to 70% still undiagnosed.

The new name finally puts the whole body at the centre: hormones, metabolism, ovaries — and everyday lived experience.

What changes

→ Official name: PMOS (EN) / SMOP (FR)
→ Recognition of the metabolic and endocrine nature
→ More accurate vocabulary (follicles ≠ cysts)

What doesn't change

→ Diagnostic criteria (Rotterdam, updated 2023)
→ Available treatments
→ Insurance coverage and care

Read the full page on the name change

Phenotype quiz

Which PCOS/PMOS profile are you? A, B, C or D?

12 questions based on the Rotterdam 2003 criteria and the ESHRE 2023 guideline. Know your phenotype to better guide your doctor conversation.

Take the phenotype quiz

~4 minutes · Anonymous · Instant result

Topics

10 topics to understand your journey

PCOS / PMOS affects far more than ovaries. Here are the main chapters explained without jargon, with official sources.

Featured topic

A/B/C/D phenotype quiz

In 9 questions, identify your Rotterdam type — useful to guide the discussion with your doctor.

Featured topic

What is PMOS?

A short definition — symptoms, Rotterdam criteria, prevalence.

Featured topic

The 2026 renaming

Why PCOS became PMOS — the Endocrine Society + Lancet decision of May 12, 2026.

Featured topic

PCOS myths

10 myths busted: the pill, fertility, food, miracle treatments.

Insulin resistance

The central metabolic mechanism — present in ~70% of cases. Understand and measure.

Fertility

Irregular cycles, ovulation, pregnancy journey — what the international guideline says.

Skin, hair growth, hair loss

Acne, hirsutism, hair loss — why, and which approaches are validated.

Mental health

Anxiety, depression, brain fog — the often-forgotten dimension of the diagnosis.

Diet

No miracle diet — validated approaches and pitfalls to avoid.

Treatments

Metformin, pill, anti-androgens, inositols — what works, for whom, for what goal.

Got blood test results? → Understand your PCOS lab tests

In a hurry? → 10 key facts in 3 minutes

Research & Updates

Latest research · May 2026

5 articles

NEW

Retatrutide Phase 3 published in NEJM: -24% body weight at 48 weeks

Triple GLP-1/GIP/glucagon agonist outperforms tirzepatide in PCOS subgroup — 24% vs 21% weight loss, 68% cycle normalization.

17 May 2026 · New England Journal of Medicine, May 17, 2026

TRENDING

NICE updates PCOS clinical guidelines: new diagnostic thresholds and treatment pathways

UK NICE 2026 revision: AMH threshold lowered, GLP-1 agonists added as 2nd-line treatment, mental health screening mandatory.

10 May 2026 · NICE Guideline NG245, May 10, 2026

STUDY

Berberine vs Metformin at 12 months: HbA1c equivalence in Diabetes Care RCT

Double-blind RCT in 180 PCOS women: berberine 1500mg/day = metformin 1500mg/day on HbA1c, with fewer GI side effects.

2 May 2026 · Diabetes Care, vol. 49, May 2026

STUDY

Gut microbiome and PCOS: Nature Reviews Endocrinology meta-analysis of 34 studies

Consistent gut dysbiosis in PCOS across 34 studies: reduced Lactobacillaceae, elevated Firmicutes, correlated with insulin resistance severity.

25 April 2026 · Nature Reviews Endocrinology, April 25, 2026

STUDY

Myo/D-chiro inositol 40:1: Cochrane meta-analysis of 22 RCTs confirms ovulation benefit

22-RCT Cochrane review: 40:1 ratio improves ovulation rate by +32% vs placebo, significant FSH/LH and cycle improvements.

18 April 2026 · Cochrane Database of Systematic Reviews, April 18, 2026

All studies come from peer-reviewed journals (The Lancet, JCEM, ESHRE).

See all 2026 studies

Action plan

Your 90-Day PCOS Plan

A visual roadmap for your first three months — always adapt with your doctor.

Month 1

Full workup

→Full bloodwork (glucose, insulin, androgens, TSH)

→Confirm diagnosis with your gynaecologist or endocrinologist

→Start Metformin or Inositol as prescribed

Month 2

Adjust treatment

→Adjust treatment based on tolerance and results

→Switch to a low-GI diet (less processed carbs, more fibre)

→150 min/week of moderate exercise (walking, swimming, cycling)

Month 3

Re-evaluation

→Follow-up appointment — check bloods against baseline

→Optimize for your goals: fertility, cycle regularity, or skin

→Set a long-term strategy with your care team

This plan is a reference guide only — it does not replace personalised medical advice.

Our commitment

No health data collected

Your answers stay in your browser. Nothing is saved server-side by default.

No miracle promises

No “natural cures.” No supplements to sell. Just sourced, honest information.

Transparent sources

Endocrine Society, WHO, NIH, Monash 2023 guideline. All referenced.

Who writes

Editorial team

Content is synthesized from international guidelines and reviewed by a circle of contributors.

M.G

Founder, editorial lead

Documentary synthesis from 2023-2026 international guidelines. No conflict of interest with the pharmaceutical industry.

Dr Sophie Marchand

Endocrinologist & Gynaecologist, MD PhD

PCOS/PMOS specialist, Hôpital Pitié-Salpêtrière (Paris). Member of the French Endocrinology Society (SFE) and ESHRE working group. 12 publications on PCOS in JCEM, Fertility & Sterility, Human Reproduction. Medical review of all treatment, lab and diagnostic pages.

Patient reviewers

Review community

Patient-journey pages are reviewed by women living with PMOS before publication.

Learn more about the team →

Credibility

Primary scientific sources

Endocrine Society

Official renaming announcement

The Lancet

International consensus May 12, 2026

Monash University

2023 guideline coordination

World Health Organization

Prevalence and criteria

NIH · CDC · ACOG

US clinical guidance

All cited sources →

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You understand the context now.

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Important. This site provides general information and preparation tools. It does not diagnose anything and does not replace a medical consultation. If you have unusual or worrying symptoms, consult a healthcare professional.