PCOS Is Now PMOS. And It's About Time.
Sometimes medicine changes a word because the original word was outdated, poorly defined, or potentially doing more harm. You could argue that this is one of those moments.
After years of global collaboration between clinicians, researchers, patients, and advocacy organisations, polycystic ovary syndrome - the condition most of us have known as PCOS - has been officially renamed polyendocrine metabolic ovarian syndrome, or PMOS.
The announcement was made this week, 12 May 2026, in a landmark paper published in The Lancet, led by an international consortium including the UK charity Verity, Australia's Monash University, and the Androgen Excess and PCOS Society.
The outcome is a name change, but how impactful is this really for women’s health and their treatment plans or protocols?
Where the old name came from
The story of PCOS begins in 1935, when two Chicago surgeons - Irving Stein and Michael Leventhal - described patients with menstrual disorders and infertility whose ovaries appeared enlarged and studded with small, cyst-like structures. They named what they could see. The term "polycystic ovary syndrome" followed, and the cyst remained the headline for nearly a century.
Except that those structures were never actually cysts. They were follicles - immature egg sacs arrested in early development because of hormonal disruption. Elevated androgens interfere with normal ovulation, leaving multiple follicles stalled on the ovary's surface. On ultrasound, they can look striking. But the ovary isn't the source of the problem; it's the site of a downstream effect.
The real disruption is happening upstream - in insulin signalling, in androgen production, in the communication between the brain, pituitary, and ovaries, and in the broader metabolic environment in which all of those signals travel.
Naming the condition after what it looked like, rather than what it was, led generations of women and their clinicians to look in the wrong place.
What PMOS actually means, and why it matters
PMOS - polyendocrine metabolic ovarian syndrome. The three words do specific work.
Polyendocrine acknowledges that more than one hormonal pathway is involved. Insulin resistance drives excess androgen production, disrupting the LH/FSH ratio, affecting oestrogen and progesterone balance, and influencing cycle regularity, mood, skin, and hair. The hypothalamic-pituitary-adrenal axis, the thyroid, the gut, and the immune system can all be in active conversation with this dysregulation.
Hormones do not function in isolation. The body operates through dynamic communication between the brain, ovaries, adrenals, thyroid, gut, metabolism, and immune system.
Metabolic places insulin resistance at the centre of the diagnosis, where it belongs. PMOS carries significantly elevated long-term risks of type 2 diabetes, cardiovascular disease, liver conditions and metabolic syndrome. These aren't coincidental comorbidities; they're expressions of the same underlying dysregulation. A name that omitted metabolism was never giving anyone the full picture.
Ovarian keeps ovulation, cycle regularity, and fertility in frame. They are affected and important, but the overall condition is not reduced to gynaecological issues alone.
What this means for women's health
PMOS affects around one in eight women - an estimated 170 million people worldwide - yet up to 70% may remain undiagnosed. The name has not been innocent in that. When a condition is called polycystic ovary syndrome, the clinical conversation tends to start and end with the ovaries. Irregular periods. Fertility concerns. Ultrasound findings. And all while the broader picture gets missed.
Because PMOS is not simply a gynaecological condition. It is a whole-body metabolic syndrome with gynaecological features. Women with PMOS may experience insulin resistance driving energy instability and blood sugar dysregulation. Elevated androgens affecting skin, hair, and mood. Anxiety and depression as expressions of the neurological and hormonal environment the condition creates. Disrupted sleep, altered gut microbiome function, heightened inflammation. None of these symptoms exist in isolation.
The name change provides formal permission in clinical settings, research, and patient conversations to approach PMOS as the whole-body condition it is. To screen for metabolic risk alongside reproductive function and to stop telling women their symptoms are unrelated, gynecologically complex or just “painful periods”.
Wouldn't that be a start?
In nutrition and lifestyle medicine, we've always known this
For those of us working in nutritional and lifestyle medicine, the PMOS rename feels less like a revelation and more like a vindication, because we have not accepted that the origin of this condition lies in a single organ.
When a woman presents with what was PCOS, we look at blood sugar patterns and insulin sensitivity, cortisol and stress load, thyroid function, gut health, nutrient status and inflammation balance. What she's eating, how she's sleeping, how her nervous system is regulated. We look at the relationship between her metabolic environment and her hormonal output because those things are (and have always been) inseparable.
The dysregulation driving PMOS is not happening because something is broken. It is happening because multiple interconnected systems are operating in an environment that isn't supporting them. So to all the women reading this, please hear this loud and clear: You are not broken. Your biology is responding, loudly, to signals worth listening to.
This whole-body understanding is not new to nutritional and lifestyle medicine. What is new is that the formal diagnosis and allopathic framing are finally catching up.
A precedent worth noting and a question worth asking
This isn't the first time medicine has corrected a condition name to reflect its metabolic reality. In 2023, non-alcoholic fatty liver disease (NAFLD) was renamed metabolic dysfunction-associated steatotic liver disease (MASLD), following a consensus process involving over 200 experts. The old name defined the condition by what it wasn't, carried stigma around the word "fatty," and failed to direct clinical attention toward the metabolic mechanisms driving it - insulin resistance, visceral adiposity, and systemic inflammation.
Sound familiar? The parallel with PMOS is direct. Both conditions were named for an observable finding rather than an underlying cause, both names misdirected care, but both have now been corrected - and that is ok. Science is constantly evolving, and to be a good scientist, you have to be ready to challenge defined understanding and be open to updating what you know.
But this raises an obvious question for me: should endometriosis be next? What we now understand about endometriosis reaches far beyond tissue found outside the uterus. It involves immune dysfunction, systemic inflammation, neurological sensitisation, gut involvement, and metabolic consequences. The name describes an anatomical observation. It says nothing about the whole-body inflammatory condition it actually is - and there is a real possibility that it is pointing clinicians in the wrong direction, just as PCOS has been doing for nearly a century.
Is the 21st century the moment women's health is finally taken seriously?
For too long, complex conditions in women have been dismissed or minimised. "It's her hormones" has been a way to end a conversation rather than begin one. (Did you hear my eye roll?)
The PMOS rename is part of something larger: a growing recognition that women's bodies are not a niche subspecialty of a male default and that when a woman's endocrine system is dysregulated, the effects are metabolic, cardiovascular, neurological, and immunological. All of those dimensions deserve genuine investigation and care.
We are in a moment of accelerating understanding of the gut-brain-hormone axis, the role of inflammation in cycle disorders, and how sleep, stress, nutrition, and movement shape endocrine function at a molecular level. PMOS is a good word - miles better than PCOS - and closer to the accuracy of what is at play biochemically.
It is long overdue, but (and there is a big but) for primary and secondary healthcare to improve, we need clinicians to continue to see the holistic picture of every patient, not just the diagnosis.
Wouldn't it be something if the 21st century turned out to be the century in which women's health was truly seen as more than just "it's her hormones".
Read - Men Have Hormones Too, The Ad That Struck A Nerve
Words by Natalie Louise Burrows for The Well Edit
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